### Automated QM/MM Setup with ORCAFF Source: https://www.faccts.de/docs/orca/6.1/manual/contents/multiscalesimulations/qmmm-general.html Configure automated QM/MM setup using ORCAFF parameters, specifying core atoms and fragmentation procedures. This example uses a PDB file for atom definition and requires ORCAFF parameter files. ```input ! QMMMSetup # just do the preparation and stop ! QMMM %qmmm ORCAFFFilename "reactant.ORCAFF.prms" QMCoreAtoms {183 2745} end ActiveCoreAtoms {183 2745} end frag FragProc SEQBACKBONE, AASCFINEGRAINED, FUNCTIONALGROUPS, EXTEND, Connectivity UseTopology true TopolFile "reactant.ORCAFF.prms" end end *pdbfile 0 1 reactant.pdb ``` -------------------------------- ### Basic QM/QM2/MM Calculation Setup Source: https://www.faccts.de/docs/orca/6.1/manual/contents/multiscalesimulations/qmmm-molecules.html An example configuration for a QM/QM2/MM calculation, specifying the ORCA force field file, atom selections for QM and QM2 regions, active atoms, and system charge. ```qmmm !QM/HF-3c/MM Opt B3LYP def2-TZVP def2/J NumFreq %qmmm ORCAFFFilename "peptideChain.ORCAFF.prms" QMAtoms {16:33 68:82} end QM2Atoms {0:12 83:104} end ActiveAtoms { 0:38 65:120} end Charge_Medium 0 end *pdbfile -1 1 peptideChain.pdb ``` -------------------------------- ### CIM-RI-MP2 Calculation Setup Source: https://www.faccts.de/docs/orca/6.1/manual/_sources/contents/modelchemistries/mdci.md.txt Example configuration for performing a CIM-RI-MP2 calculation. Specifies the RI-MP2 method, basis sets, and custom CIM threshold. ```orcainput # # CIM-RI-MP2 calculation # ! RI-MP2 cc-pVDZ cc-pVDZ/C CIM %CIM CIMTHRESH 0.0005 # Default value is 0.001 end * xyzfile 0 1 CIM.xyz ``` -------------------------------- ### NEVPT2 Calculation Setup Source: https://www.faccts.de/docs/orca/6.1/manual/contents/modelchemistries/NEVPT2.html Example of setting up a NEVPT2 calculation using simple input or the %casscf block. Note the spelling difference between simple input ('SC-NEVPT2') and block input ('SC_NEVPT2'). ```input !def2-svp nofrozencore PAtom %casscf nel 6 norb 6 mult 1 PTMethod SC_NEVPT2 # SC_NEVPT2 for strongly contracted NEVPT2 # FIC_NEVPT2 for the fully internally # contracted NEVPT2 # DLPNO_NEVPT2 for the FIC-NEVPT2 with DLPNO # DLPNO requires: trafostep RI and an aux basis end * xyz 0 1 N 0.0 0.0 0.0 N 0.0 0.0 1.09768 * ``` -------------------------------- ### Basic QM/QM2/MM Calculation Setup Source: https://www.faccts.de/docs/orca/6.1/manual/_sources/contents/multiscalesimulations/qmmm-molecules.md.txt An example configuration for a QM/QM2/MM calculation, specifying the ORCA functional, basis sets, MM force field file, and the atom lists for QM, QM2, and active regions. ```orca !QM/HF-3c/MM Opt B3LYP def2-TZVP def2/J NumFreq %qmmm ORCAFFFilename "peptideChain.ORCAFF.prms" QMAtoms {16:33 68:82} end QM2Atoms {0:12 83:104} end ActiveAtoms { 0:38 65:120} end Charge_Medium 0 end *pdbfile -1 1 peptideChain.pdb ``` -------------------------------- ### Basic MOL-CRYSTAL-QMMM Calculation Setup Source: https://www.faccts.de/docs/orca/6.1/manual/_sources/contents/multiscalesimulations/qmmm-crystal.md.txt An example of a basic MOL-CRYSTAL-QMMM calculation, specifying the QM/MM method, DFT functional, basis set, optimization, frequency calculation, QM atoms, and active atoms, along with the input XYZ file. ```orcainput ! MOL-CRYSTAL-QMMM ! PBE def2-SVP Opt NumFreq %qmmm NUnitCellAtoms 13 QMAtoms {221:233} end ActiveAtoms {221:233} end end *xyzfile 0 1 Ala_SC.xyz ``` -------------------------------- ### Automated QM/Active Region Setup with Fragmentation Source: https://www.faccts.de/docs/orca/6.1/manual/_sources/contents/multiscalesimulations/qmmm-general.md.txt Use the QMMMSetup keyword and fragmentation procedures to automatically determine QM and active regions based on core atoms and system topology. This example uses RNA and ligand-specific fragmentation. ```orca ! QM/XTB ! QMMMSetup # just do the preparation and stop %qmmm QMCoreAtoms {2032} end ActiveCoreAtoms {2032} end frag FragProc NABackbone, NASideChains, FunctionalGroups, Extend, Connectivity end end *xyz 0 1 ``` -------------------------------- ### Install OPI from GitHub Source: https://www.faccts.de/docs/orca/6.1/manual/contents/workflowsautomatization/orcapythoninterface.html Install OPI by cloning the GitHub repository and setting up a virtual environment. This method allows for direct access to the source code and development versions. ```bash git clone https://github.com/faccts/opi.git cd opi python3 -m venv .venv source .venv/bin/activate python3 -m pip install . ``` -------------------------------- ### For Loop Example Source: https://www.faccts.de/docs/orca/6.1/manual/_sources/contents/workflowsautomatization/compounddetails.md.txt Demonstrates a 'For' loop for repetitive tasks. The loop variable iterates from a start value to an end value, inclusive. Both start and end values must be integers. ```orca For i From 1 To 10 Do ! commands EndFor; ``` -------------------------------- ### Demonstrate GoTo Command Source: https://www.faccts.de/docs/orca/6.1/manual/_sources/contents/workflowsautomatization/compound_examples.md.txt This example demonstrates the usage of the GoTo command within Compound workflows. ```orca %compound GoTo "step2" %end step1 ! Some calculation RUNTYP HF %pal nprocs 8 end * xyz 0 1 H 0 0 0 * step2 ! Another calculation RUNTYP SP %pal nprocs 8 end * xyz 0 1 H 0 0 1 * ``` -------------------------------- ### ORCA Comment Example Source: https://www.faccts.de/docs/orca/6.1/manual/_sources/contents/essentialelements/input.md.txt Illustrates how to add single-line comments in an ORCA input file, starting with '#'. ```orca # This is a comment. Continues until the end of the line ``` -------------------------------- ### Example Basis Set File Format (3-21GSP) Source: https://www.faccts.de/docs/orca/6.1/manual/_sources/contents/essentialelements/basisset.md.txt This is an example of the file format for defining a basis set, compatible with GAMESS-US. Lines starting with '!' or '#' are comments. Element symbols and shell types (S, L) are used. ```text ! lines in the beginning with '!' or '#' are comments ! BASIS="3-21GSP" !Elements References !-------- ---------- ! H - Ne: A.V. Mitin, G. Hirsch, R. J. Buenker, Chem. Phys. Lett. 259, 151 (1996) ! Na - Ar: A.V. Mitin, G. Hirsch, R. J. Buenker, J. Comp. Chem. 18, 1200 (1997). ! $DATA ! Optional HYDROGEN ! (3s) -> [2s] Element symbols are also recognized S 2 1 4.50036231 0.15631167 2 0.68128924 0.90466909 S 1 1 0.15137639 1.00000000 CARBON ! (6s,3p) -> [3s,2p] S 3 1 499.24042249 0.03330322 2 75.25419194 0.23617745 3 16.86538669 0.81336259 L 2 ! L shells are a s and a p shell with identical exponents 1 0.89739483 0.24008573 0.46214684 2 0.21746772 0.81603757 0.66529098 L 1 1 4.52660451 1.00000000 1.00000000 $END ! Optional ``` -------------------------------- ### LED Example Input Source: https://www.faccts.de/docs/orca/6.1/manual/contents/spectroscopyproperties/led.html Example input file for analyzing the interaction of H2O with CH2 using the LED framework with PBE0-D3/def2-TZVP. ```input ! dlpno-ccsd(t) cc-pvdz cc-pvdz/c cc-pvtz/jk rijk verytightscf TightPNO LED *xyz 0 1 C(1) 0.16044643459993 0.10093183177121 0.22603351276210 H(1) 1.04516129053973 -0.06834886965353 -0.41865951747519 H(1) -0.12579332868173 1.14737893892114 0.00305818518771 O(2) -1.48285705560792 -1.31933824653169 2.29891474420047 H(2) -0.91417368674145 -0.93085192992263 1.60917234463506 H(2) -1.15648922489703 -2.21246650333085 2.42094328175662 * ``` -------------------------------- ### CIM-DLPNO-CCSD(T) Calculation Setup Source: https://www.faccts.de/docs/orca/6.1/manual/_sources/contents/modelchemistries/mdci.md.txt Example configuration for performing a CIM-DLPNO-CCSD(T) calculation. Specifies the DLPNO-CCSD(T) method and basis sets. ```orcainput # # CIM-DLPNO-CCSD calculation # ! DLPNO-CCSD(T) cc-pVDZ cc-pVDZ/C CIM * xyzfile 0 1 CIM.xyz ``` -------------------------------- ### Comprehensive ORCA Configuration Example Source: https://www.faccts.de/docs/orca/6.1/manual/contents/utilitiesvisualization/orca_2json.html An example configuration file enabling basis set information and specific integrals, requesting all densities, and setting output formats to ASCII JSON and binary JSON. ```json { "MOCoefficients": false, "Basisset": true, "1elPropertyIntegrals": ["dipole", "quadrupole", "velocity", "printLinMom", "angular_momentum", "higherMoment", "soc"], "1elPropertyRelIntegrals": ["dipole", "quadrupole", "angular_momentum", "soc"], "1elIntegrals": ["H", "S", "T", "V", "HMO"], "1elIntegralsRel": ["H", "S", "T", "V", "HMO"], "FockMatrix": ["F", "J", "K", "VXC", "Vsol"], "Vaux": false, "AuxBasisType": "AuxC", "FullTrafo": false, "OrbWin": [0,0,0,0,0,0,0,0], "2elIntegrals": [ "MO_IJKL", "RI_IAV", "RI_IJKL"], "2elNonRedIntegrals": false, "2elNonRedRIIntegrals": false, "MullikenCharge": false, "LoewdinCharge": false, "Densities": ["all"], "JSONFormats": ["json", "bson"] } ``` -------------------------------- ### Compound GoTo Example for ON/OFF Switch Source: https://www.faccts.de/docs/orca/6.1/manual/contents/workflowsautomatization/compound_examples.html This script demonstrates the GoTo command in Compound to create an efficient ON/OFF switch. It uses conditional logic to navigate between 'turnOff' and 'turnOn' labels, toggling a switch variable and printing its state. The loop continues until a maximum iteration count is reached. ```Compound # Compound Example on GoTo usage # Efficient ON/OFF switch %Compound Variable switch="OFF"; Variable turnOff, turnOn, loopEnd; Variable maxIter = 10; for i from 0 to maxIter do if (switch="ON") then GoTo turnOff; else GoTo turnOn; endIf turnOff: print("Switch: %s\n", switch); switch="OFF"; GoTo loopEnd; turnON: print("Switch: %s\n", switch); switch="ON"; GoTo loopEnd; loopEnd: EndFor End ``` -------------------------------- ### Initial LED Analysis Setup Source: https://www.faccts.de/docs/orca/6.1/tutorials/prop/led.html This snippet shows the input file configuration for an initial LED analysis. It specifies the calculation method, basis sets, and the 'LED' keyword to enable the decomposition. Fragments are defined using the '*XYZ' block. ```input !DLPNO-CCSD(T) DEF2-SVP DEF2-SVP/C DEF2/J RIJCOSX VERYTIGHTSCF TIGHTPNO LED *XYZ 0 1 C(1) -4.46463 -0.12110 0.22162 [...] O(1) -0.99391 0.49487 -2.78478 C(2) 0.15487 -0.43421 0.93360 [...] H(2) 5.37983 -0.86517 1.10337 * ``` -------------------------------- ### Example ORCA Property Block Source: https://www.faccts.de/docs/orca/6.1/manual/_sources/contents/utilitiesvisualization/property_file.md.txt Demonstrates a typical property block starting with '$' and ending with '$End', containing various components. ```orca $SCF_Nuc_Gradient &GeometryIndex 1 &NAtoms [&Type "Integer"] 2 &gradNorm [&Type "Double"] 7.6940943132805237e-02 &grad [&Type "ArrayOfDoubles", &Dim (6,1)] 0 0 6.7009699964043727e-10 1 -1.3755030800675890e-10 2 5.4405462640094826e-02 3 -6.7009699282161039e-10 4 1.3755031156980307e-10 5 -5.4405462640095381e-02 &Method [&Type "String"] "SCF" &Level [&Type "String"] "Relaxed density" &Mult [&Type "Integer"] 1 &State [&Type "Integer"] 0 &Irrep [&Type "Integer"] 0 $End ``` -------------------------------- ### ORCA CCSD/CPCM Output Snippet Source: https://www.faccts.de/docs/orca/6.1/manual/_sources/contents/essentialelements/solvationmodels.md.txt Example output from ORCA showing the selected CCSD/C-PCM scheme. This helps in verifying the calculation setup. ```text -------------------------------------------------------------------------------- ORCA-MATRIX DRIVEN CI -------------------------------------------------------------------------------- -------------------------------- AUTOMATIC CHOICE OF INCORE LEVEL -------------------------------- Memory available ... 2000.00 MB Memory needed for S+T ... 9.26 MB Memory needed for J+K ... 18.57 MB Memory needed for DIIS ... 129.61 MB Memory needed for 3-ext ... 72.69 MB Memory needed for 4-ext ... 486.14 MB Memory needed for triples ... 0.00 MB -> Final InCoreLevel ... 5 Wavefunction type ----------------- Correlation treatment ... CCSD Single excitations ... ON Orbital optimization ... OFF Calculation of Lambda equations ... ON Calculation of Brueckner orbitals ... OFF Perturbative triple excitations ... OFF CPCM scheme ... PTE(S) Calculation of F12 correction ... OFF ``` -------------------------------- ### ORCA ArrayOfDoubles Component Example Source: https://www.faccts.de/docs/orca/6.1/manual/contents/utilitiesvisualization/property_file.html Array components, like 'ArrayOfDoubles', specify dimensions and then present data in blocks, starting with column indices. ```text &dipoleTotal [&Type "ArrayOfDoubles", &Dim (3,1)] "Total" 0 0 -5.1716015643064861e-01 1 5.1774970936823518e-02 2 7.8324050140722279e-01 ``` -------------------------------- ### Example ORCA Property Block Source: https://www.faccts.de/docs/orca/6.1/manual/contents/utilitiesvisualization/property_file.html A typical property block starts with '$' followed by the property name and ends with '$End'. It contains components denoted by '&'. ```text $SCF_Nuc_Gradient &GeometryIndex 1 &NAtoms [&Type "Integer"] 2 &gradNorm [&Type "Double"] 7.6940943132805237e-02 &grad [&Type "ArrayOfDoubles", &Dim (6,1)] 0 0 6.7009699964043727e-10 1 -1.3755030800675890e-10 2 5.4405462640094826e-02 3 -6.7009699282161039e-10 4 1.3755031156980307e-10 5 -5.4405462640095381e-02 &Method [&Type "String"] "SCF" &Level [&Type "String"] "Relaxed density" &Mult [&Type "Integer"] 1 &State [&Type "Integer"] 0 &Irrep [&Type "Integer"] 0 $End ``` -------------------------------- ### CI Setup and Solution Block Source: https://www.faccts.de/docs/orca/6.1/manual/contents/utilitiesvisualization/utilities.html This block shows the process of defining CI spaces and setting up the CI problem. It includes checks for multiplicity, number of configurations, CSF's, and roots, followed by the actual CI setup. ```text => Defining the CI spaces and setting up the CI ... ============================================================================== CI SETUP AND SOLUTION BLOCK ============================================================================== Making Checks... Multiplicty = 3, #(configurations) = 28 #(CSF's) = 28 #(Roots) = 25 NRoots (CSF's) = 25 Setting up CI... Multiplicty = 3, #(configurations) = 28 #(CSF's) = 25 #(Roots) = 25 ============================================================================= CI SETUP AND SOLUTION BLOCK ============================================================================= Making Checks... Multiplicty = 1, #(configurations) = 36 #(CSF's) = 36 #(Roots) = 30 NRoots (CSF's) = 30 Setting up CI... Multiplicty = 1, #(configurations) = 36 #(CSF's) = 30 #(Roots) = 30 CI setup done ``` -------------------------------- ### Start UMA Server Source: https://www.faccts.de/docs/orca/6.1/tutorials/workflows/extopt.html Starts the UMA server for external model calculations. Ensure you are logged into HuggingFace and have access to the UMA repository. ```bash oet_server uma ``` -------------------------------- ### QMMM Configuration Example Source: https://www.faccts.de/docs/orca/6.1/manual/_sources/contents/multiscalesimulations/qmmm-general.md.txt Example of configuring QMMM calculations using various keywords within the %qmmm block. This includes settings for extending the active region, print levels, and nonbonded interactions. ```orca !QMMM %qmmm # The extended active region, activeRegionExt, contains the atoms surrounding the # active atoms. ExtendActiveRegion distance # rule to choose the atoms belonging # to activeRegionExt. # no - do not use activeRegionExt atoms # cov_bonds - add only atoms bonded covalently to # active atoms # distance (default) - use a distance criterion (VDW # distance plus Dist_AtomsAroundOpt) Dist_AtomsAroundOpt 0.0 # in Angstrom (Default 0). Meaning only freeze atoms # which touch the active atoms by their VDW spheres. # only needed for ExtendActiveRegion distance OptRegion_FixedAtoms {27 1288:1290 4400} end # manually define the # activeRegionExt atoms. # Default: empty list. # Printing options. All are true by default. PrintLevel 1 # Can be 0 to 4, 0=nothing, 1=normal, ... PrintOptRegion true # Additionally print xyz and trj for opt region PrintOptRegionExt false # Additionally print xyz and trj for extended # opt region PrintQMRegion true # Additionally print xyz and trj for QM region PrintFullTRJ true # Print trajectory of full system. Default true. PrintPDB true # Additionally print pdb file for entire system, is # updated every iteration for optimization # Computing MM nonbonded interactions within non-active region. Do_NB_For_Fixed_Fixed true # Compute MM-MM nonbonded interaction also for # non-active atom pairs. Default true. # Treats all active water molecules that are treated on MM level as rigid bodies # in optimization and MD simulation, see section "Rigid Water". Rigid_MM_Water false # Default false. end *pdbfile 0 1 ubq.pdb # structure input via pdb file, but also possible via # xyz file ``` -------------------------------- ### DLPNO-NEVPT2-F12 Calculation Setup Source: https://www.faccts.de/docs/orca/6.1/manual/contents/modelchemistries/NEVPT2.html Example input for a DLPNO-NEVPT2-F12 calculation, a linear scaling variant. The input structure is identical to NEVPT2-F12, with the exception of the DLPNO_NEVPT2 keyword. ```input # aug-cc-pvdz/C used as RI basis ! cc-pvdz-F12 aug-cc-pvdz/C cc-pvdz-f12-cabs %casscf nel 8 norb 6 mult 3,1 # mandatory: TrafoStep RI # RI approximation must be on for F12 PTMethod DLPNO_NEVPT2 # DLPNO variant PTSettings F12 true # request the F12 correction and CABS singles correction. end end *xyz 0 3 O 0.0 0.0 0.0 O 0.0 0.0 1.207 * ``` -------------------------------- ### Detailed LED Configuration in %mdci Block Source: https://www.faccts.de/docs/orca/6.1/manual/contents/spectroscopyproperties/led.html This example demonstrates how to configure the Local Energy Decomposition (LED) using the %mdci block. It includes settings for the localization method (PipekMezey or FosterBoys), print level, maximum iterations, localization tolerance, skipping CCSD iterations, and decomposing the reference energy. ```input %mdci LED 1 # localization method for the PNOs. Choices: # 1 = PipekMezey # 2 = FosterBoys (default starting from ORCA 4.2) PrintLevel 3 # Selects large output for LED and prints the # detailed contribution # of each DLPNO-CCSD strong pair LocMaxIterLed 600 # Maximum number of localization iterations for PNOs LocTolLed 1e-6 # Absolute threshold for the localization procedure for PNOs Maxiter 0 # Skips the CCSD iterations and # the decomposition of the correlation energy DoLEDHF true # Decomposes the reference energy in the LED part. # By default, it is set to true. end ``` -------------------------------- ### Basic Input Block Structure Source: https://www.faccts.de/docs/orca/6.1/manual/contents/essentialelements/input.html Input blocks in ORCA start with '%', followed by the block name and end with 'END'. This example shows a simple '%method' block. ```text %method method HF END ``` -------------------------------- ### Define an ORCA Input Block Source: https://www.faccts.de/docs/orca/6.1/manual/_sources/contents/essentialelements/input.md.txt Input blocks in ORCA start with '%', followed by the block name and end with 'END'. This example shows a basic '%method' block. ```orca %method method HF END ``` -------------------------------- ### Open Shell LED Example Input File Source: https://www.faccts.de/docs/orca/6.1/manual/_sources/contents/spectroscopyproperties/led.md.txt An example input file for an open shell DLPNO-CCSD(T) calculation using the LED scheme. The output is equivalent to the closed-shell case. ```orcainput ! ``` -------------------------------- ### Write2File Command Example Source: https://www.faccts.de/docs/orca/6.1/manual/_sources/contents/workflowsautomatization/compounddetails.md.txt Demonstrates how to use the Write2File command to write formatted output to a file. Ensure the file is opened with OpenFile and closed with CloseFile. ```orca ! This is a comment ! Example for Write2File command ! First, open a file OpenFile(my_output_file, "output.txt") ! Then, write formatted data to it Write2File(my_output_file, "Hello, %s! The value is %f.\n", "World", 3.14159) ! Finally, close the file CloseFile(my_output_file) ``` -------------------------------- ### Get Bond Distance Between Two Atoms Source: https://www.faccts.de/docs/orca/6.1/manual/_sources/contents/workflowsautomatization/compounddetails.md.txt Returns the distance in Bohrs between two specified atoms within a geometry object. Atom indexing starts from zero. ```orca ! GEOMETRY GetBondDistance(atomA=0, atomB=1) ! END ``` -------------------------------- ### Basic sTD-DFT Calculation Setup Source: https://www.faccts.de/docs/orca/6.1/manual/_sources/contents/spectroscopyproperties/tddft.md.txt Invoke a standard sTD-DFT calculation by replacing 'Mode sTDA' with 'Mode sTDDFT'. This example uses the \omegaB97X functional with default parameters. ```orca ! wb97x def2-SVP tightscf smallprint printgap nopop %tddft Mode sTDDFT Ethresh 10.0 axstda 0.56 beta1 8.00 beta2 0.00 alpha1 4.58 alpha2 0.00 end *xyz 0 1 N -1.726176 0.687742 -0.007335 N 1.213763 0.735949 -0.027163 N -1.545188 -2.243058 -0.016803 N 1.395005 -2.195166 -0.036972 C 2.736733 -1.895646 -0.045209 C 3.277248 -0.608637 -0.045175 C 2.575908 0.605756 -0.036945 C 0.977551 2.083559 -0.021690 C -0.288108 2.687287 -0.011220 C -1.529488 2.048274 -0.004419 C -3.067756 0.388045 0.001354 H -0.976948 -0.007843 -0.015911 C -3.608477 -0.899096 0.001258 C -2.907149 -2.113434 -0.007085 C -1.308388 -3.590806 -0.022331 C -0.042695 -4.194596 -0.032673 C 1.198590 -3.555847 -0.039419 H 0.645751 -1.499625 -0.028098 C -3.768181 1.641701 0.010433 C -2.832985 2.651061 0.006924 C 2.228928 2.835679 -0.028158 C 3.228183 1.912006 -0.037679 C 3.437220 -3.149227 -0.053963 C 2.502048 -4.158627 -0.050442 C -3.558669 -3.420017 -0.006390 C -2.559381 -4.343652 -0.015901 H -4.633051 -3.589818 0.000518 H -2.644718 -5.427990 -0.018393 H -0.016400 -5.285446 -0.035842 H 2.681678 -5.229875 -0.055110 H 4.519010 -3.247119 -0.061999 H 4.366739 -0.548807 -0.052422 H 2.314239 3.920088 -0.025633 H 4.302487 2.081864 -0.044563 H -0.315062 3.778120 -0.007889 H -3.013895 3.722099 0.011827 H -4.849852 1.740964 0.018679 H -4.697992 -0.958441 0.008649 end ``` -------------------------------- ### Initial SINGLE_ANISO Calculation Setup Source: https://www.faccts.de/docs/orca/6.1/manual/contents/spectroscopyproperties/single_aniso.html This snippet shows the initial setup for a SINGLE_ANISO calculation, including relativistic effects for heavier elements and convergence smoothing. It generates an orbital file for subsequent steps. ```input !DKH DKH-DEF2-SVP TightSCF conv Moread %moinp "CeCOT2_1.gbw" %basis newgto Ce "SARC2-DKH-QZVP" end end %casscf nel 1 norb 7 # 1 electrons in 7 f orbitals mult 2 nroots 7 # 7 doublet states rel dosoc true # include spin-orbit coupling end end *xyz -1 2 ...... * ``` -------------------------------- ### Basic Command Syntax with Arguments Source: https://www.faccts.de/docs/orca/6.1/manual/_sources/contents/moleculardynamics/moldyn.md.txt Illustrates the basic structure of commands with non-optional and optional arguments, showing valid ways to format them. ```orca %md Command Arg1 Arg2 Arg3 # fine Command Arg1, Arg2, Arg3 # fine Command Arg1 Arg2 Arg3 Optarg1 # fine Command Arg1 Arg2 Arg3 Optarg1 Optarg2 # fine Command Arg1 Arg2 Arg3 Optarg2 # will not work end ``` -------------------------------- ### Compound Timer Usage Example Source: https://www.faccts.de/docs/orca/6.1/manual/contents/workflowsautomatization/compounddetails.html Illustrates the declaration, start, stop, and total functions of a timer object in ORCA. Timers are used to measure execution time of code blocks. ```orca # ----------------------------------------------- # This is to test timer functions. # -------------------------------- timer tm; Variable x = 0.0; tm.start(); for index from 0 to 100000 Do x = x + 0.1; EndFor tm.stop(); x = tm.Total(); print( "------------------------------\n"); print( " Compound - Timer Results \n"); print( "------------------------------\n"); print( " First total time: %%.2lf\n", x); x = tm.total(); tm.Reset(); tm.Start(); for index from 0 to 200000 Do x = x + 0.1; EndFor tm.Stop(); x = tm.total(); print( " Second total time: %%.2lf\n", x); End ``` -------------------------------- ### Example ORCA JSON Configuration File Source: https://www.faccts.de/docs/orca/6.1/manual/_sources/contents/utilitiesvisualization/orca_2json.md.txt An example configuration file demonstrating various keywords to enable/disable specific data exports, including basis set information and integrals. ```orca { "MOCoefficients": false, "Basisset": true, "1elPropertyIntegrals": ["dipole", "quadrupole", "velocity", "printLinMom", "angular_momentum", "higherMoment", "soc"], "1elPropertyRelIntegrals": ["dipole", "quadrupole", "angular_momentum", "soc"], "1elIntegrals": ["H", "S", "T", "V", "HMO"], "1elIntegralsRel": ["H", "S", "T", "V", "HMO"], "FockMatrix": ["F", "J", "K", "VXC", "Vsol"], "Vaux": false, "AuxBasisType": "AuxC", "FullTrafo": false, "OrbWin": [0,0,0,0,0,0,0,0], "2elIntegrals": [ "MO_IJKL", "RI_IAV", "RI_IJKL"], "2elNonRedIntegrals": false, "2elNonRedRIIntegrals": false, "MullikenCharge": false, "LoewdinCharge": false, "Densities": ["all"], <--- here you specify the names like "scfp" or "scfr" or all "JSONFormats": ["json", "bson"] } ``` -------------------------------- ### Full Orca LFT Input for Nickel Complex Source: https://www.faccts.de/docs/orca/6.1/manual/contents/utilitiesvisualization/utilities.html An example input file for orca_lft demonstrating the setup of a nickel complex with custom ligand field parameters and Slater-Condon parameters. ```input %lft #-----Parameters------ NEl= 14 LFTCase 2p3d Mult= 3, 1 NRoots= 25, 30 #-------------------- #---Slater-Condon Parameters--- #---All Values in eV--- PARAMETERS F0pp = 85.88 F2pp = 54.77 F0dd = 23.31 F2dd = 13.89 F4dd = 9.14 F0pd = 33.03 F2pd = 7.76 G1pd = 6.42 G3pd = 2.11 DOh = 1.2 D1 = {-0.4*DOh} D2 = {0.6*DOh} end #-------------------- #---Diagonal LFT-Matrix Elelemnts--- #---All Values in eV--- FUNCTIONS 0 0 " 0.00" 1 1 " 0.00" 2 2 " 0.00" 3 3 "1138.35 + D2" # => dz2 4 4 "1138.35 + D1" # => dxz 5 5 "1138.35 + D1" # => dyz 6 6 "1138.35 + D2" # => dx2-y2 7 7 "1138.35 + D1" # => dxy end #-------------------- #---SOC-CONSTANTS--- #---All Values in eV--- PARAMETERS ZETA_P = 11.341 ZETA_D = 0.085 end #-------------------- #---SPECTRA/PROPERTIES--- DoABS true Rel DoSOC true End #--------- End *xyz 2 3 Ni 0.00 0.00 0.00 * ``` -------------------------------- ### NEVPT2-F12 Calculation Setup Source: https://www.faccts.de/docs/orca/6.1/manual/contents/modelchemistries/NEVPT2.html Example input for an NEVPT2-F12 calculation. Requires an F12 basis, an F12-cabs basis, and a sufficiently large RI basis. The RI approximation must be enabled. ```input # aug-cc-pvdz/C used as RI basis ! cc-pvdz-F12 aug-cc-pvdz/C cc-pvdz-f12-cabs %casscf nel 8 norb 6 mult 3,1 # mandatory: TrafoStep RI # RI approximation must be on for F12 PTMethod FIC_NEVPT2 # FIC-NEVPT2 PTSettings F12 true # request the F12 correction and CABS singles correction. end end *xyz 0 3 O 0.0 0.0 0.0 O 0.0 0.0 1.207 * ``` -------------------------------- ### ORCA Startup Warnings Example Source: https://www.faccts.de/docs/orca/6.1/manual/contents/quickstartguide/troubleshooting.html This section displays typical startup warnings from ORCA. Pay close attention to these, as they can indicate potential issues or assumptions made by ORCA that might affect the calculation results. For restart operations, ensure the correct restart options are used. ```text =========================================================================== WARNINGS Please study these warnings very carefully! =========================================================================== WARNING: Geometry Optimization ===> : Switching off AutoStart For restart on a previous wavefunction, please use MOREAD ```