### 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 ORCAFF parameters, QM, QM2, and Active atom regions, medium system charge, and the PDB file. ```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 ``` -------------------------------- ### Example of Simple Keyword Lines Source: https://www.faccts.de/docs/orca/6.1/manual/_sources/contents/essentialelements/input.md.txt Demonstrates the basic syntax of simple keyword lines, where each line starts with '!' followed by space-separated keywords. ```orca ! Keyword1 Keyword2 ! Keyword3 ``` -------------------------------- ### 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 force field file, QM, QM2, and active atom regions, medium system charge and multiplicity, and the PDB file. ```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 complete input file for a MOL-CRYSTAL-QMMM calculation, including method, basis set, optimization, frequency calculation, QM/MM settings, and the input structure 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 ``` -------------------------------- ### 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, setting up a virtual environment, and installing the package locally. This method is useful for development or when using the latest unreleased features. ```bash git clone https://github.com/faccts/opi.git cd opi python3 -m venv .venv source .venv/bin/activate python3 -m pip install . ``` -------------------------------- ### Basic MOL-CRYSTAL-QMMM Calculation Setup Source: https://www.faccts.de/docs/orca/6.1/manual/contents/multiscalesimulations/qmmm-crystal.html Example configuration for a MOL-CRYSTAL-QMMM calculation, specifying the method, basis set, optimization, frequency calculation, QM atoms, and active atoms. ```orca ! 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 ``` -------------------------------- ### Example ORCA Input for Citations Source: https://www.faccts.de/docs/orca/6.1/manual/_sources/contents/preface/howtocite.md.txt A sample ORCA input file demonstrating a basic calculation setup. The output of such a run will include recommended citations. ```text ! PBE CPCM(Water) *XYZFILE 0 1 structure.xyz ``` -------------------------------- ### Install OPI from GitHub Source: https://www.faccts.de/docs/orca/6.1/manual/_sources/contents/workflowsautomatization/orcapythoninterface.md.txt Install the ORCA Python Interface (OPI) by cloning the GitHub repository and installing it within a virtual environment. This method is useful for developers or those who need the latest unreleased features. ```bash git clone https://github.com/faccts/opi.git cd opi python3 -m venv .venv source .venv/bin/activate python3 -m pip install . ``` -------------------------------- ### sTD-DFT Calculation Setup with Custom Parameters Source: https://www.faccts.de/docs/orca/6.1/manual/contents/spectroscopyproperties/tddft.html Invokes a sTD-DFT calculation using the ωB97X functional with user-specified parameters for exchange and correlation integrals. This example demonstrates fine-tuning of the calculation beyond default settings. ```input ! 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 ``` -------------------------------- ### Compound GOAT Input Example Source: https://www.faccts.de/docs/orca/6.1/manual/_sources/contents/workflowsautomatization/compounddetails.md.txt This is an example of a Compound input file demonstrating GOAT object usage. ```orca """ # This is a comment # Example of a GOAT object declaration GOAT myGoat # Example of parsing an ensemble file myGoat.ParseEnsembleFile(filename="path/to/your/ensemble.dat") # Example of getting the number of geometries numGeom = myGoat.Get_Num_Of_Geometries() print("Number of geometries: ", numGeom) # Example of getting the energy of a specific geometry (e.g., the first one) energy = myGoat.Get_Energy(geomID=1) print("Energy of geometry 1: ", energy) # Example of setting the basename for output files myGoat.Set_Basename(myFilename="my_output_basename") # Example of writing coordinates to an XYZ file myGoat.WriteXYZFile() # Example of printing the GOAT object's content myGoat.Print() """ ``` -------------------------------- ### Run ORCA Installer on Linux/MacOS Source: https://www.faccts.de/docs/orca/6.1/manual/_sources/contents/quickstartguide/installation.md.txt Execute the ORCA installer script after making it executable. This command initiates the installation process. ```bash ./orca_6_1_0_linux_x86-64_shared_openmpi416.run ``` -------------------------------- ### Set Install Path with ORCA Installer Source: https://www.faccts.de/docs/orca/6.1/manual/_sources/contents/quickstartguide/installation.md.txt Example of using the '-p' option with the ORCA installer to specify a custom installation directory. Note the double dash '--' before the options. ```bash ./orca_6_1_0_linux_x86-64_shared_openmpi416.run -- -p /my/home/orca/dir ``` -------------------------------- ### Hello World Example Source: https://www.faccts.de/docs/orca/6.1/manual/_sources/contents/workflowsautomatization/compound_examples.md.txt Demonstrates using Compound as a driver for simple tasks like printing a message, rather than running a full ORCA calculation. ```orca ! %output Print[P_Energy] 1 FileEnd %end * xyz 0 1 C 0.0 0.0 0.0 * ``` -------------------------------- ### ORCA Broken-Symmetry Calculation Example (C05S13_233.inp) Source: https://www.faccts.de/docs/orca/6.1/manual/_sources/contents/spectroscopyproperties/magnx.md.txt This is an example input file for a broken-symmetry calculation in ORCA, demonstrating the setup for calculating singlet-triplet splitting in a stretched Li2 molecule. ```orca ! ``` -------------------------------- ### CIM-DLPNO-CCSD(T) Calculation Setup Source: https://www.faccts.de/docs/orca/6.1/manual/_sources/contents/modelchemistries/mdci.md.txt Example of how to set up a CIM-DLPNO-CCSD(T) calculation in ORCA. 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 ``` -------------------------------- ### 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. The GoTo command allows for conditional or unconditional jumps to specific sections of the input file, enabling more complex workflow logic. ```orca %compound goto_Example.inp end% %section goto_Example.inp end% ``` -------------------------------- ### Full ORCA LFT Input Example Source: https://www.faccts.de/docs/orca/6.1/manual/_sources/contents/utilitiesvisualization/utilities.md.txt A comprehensive example of an ORCA input file demonstrating the setup of a parameterized LFT model for a nickel complex. It includes defining basis sets, Slater-Condon parameters, and SOC constants. ```orca %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 * ``` -------------------------------- ### 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. ```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 ``` -------------------------------- ### Automated QM/MM Setup with Fragments Source: https://www.faccts.de/docs/orca/6.1/manual/contents/multiscalesimulations/qmmm-general.html Utilize automated fragment-based QM/MM setup. Specify core atoms and fragmentation procedures to let ORCA determine the QM and active regions. The `QMMMSetup` keyword performs the setup and stops, allowing verification. ```input ! 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 ``` ```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 ``` -------------------------------- ### ORCA Comment Example Source: https://www.faccts.de/docs/orca/6.1/manual/_sources/contents/essentialelements/input.md.txt Shows how to include comments in the ORCA input file, which start with a '#' character and extend to the end of the line. ```orca # This is a comment. Continues until the end of the line ``` -------------------------------- ### GAMESS-US Basis Set File Format Example Source: https://www.faccts.de/docs/orca/6.1/manual/contents/essentialelements/basisset.html This is an example of a basis set file format compatible with ORCA, similar to the GAMESS-US format. Lines starting with '!' are comments. Element symbols are recognized, and shells are defined by type and number of functions. ```gamess ! 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 ``` -------------------------------- ### Multi-XYZ Guest File Content Example Source: https://www.faccts.de/docs/orca/6.1/manual/contents/structurereactivity/docker.html Example content of a multi-XYZ file used for docking, containing multiple molecular structures with their respective atom coordinates. ```xyz 3 0 1 O -2.13487 2.63905 -0.01809 H -1.16698 2.61938 0.02397 H -2.41372 2.24598 0.82256 12 0 1 N -0.2707028 0.7632994 1.0276159 H -0.5957915 1.3097757 1.8163465 C -0.3386212 1.3810817 -0.2276640 O -0.7270425 2.5346295 -0.3329857 N 0.3638189 -1.2896563 0.1949192 H 0.0796815 0.9143946 -2.3190044 C 0.3781329 -0.7736192 -1.0714063 H 0.6499130 -1.4675080 -1.8526542 C 0.0669084 0.5154897 -1.3194961 H 0.4818502 -2.2779688 0.3498201 C -0.0016589 -0.5616540 1.3117092 O -0.0864879 -1.0482643 2.4227999 ``` -------------------------------- ### CIM-RI-MP2 Calculation Setup Source: https://www.faccts.de/docs/orca/6.1/manual/_sources/contents/modelchemistries/mdci.md.txt Example of how to set up a CIM-RI-MP2 calculation in ORCA. 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 ``` -------------------------------- ### Open Shell LED Example Input File Source: https://www.faccts.de/docs/orca/6.1/manual/contents/spectroscopyproperties/led.html An example of an input file for an open shell DLPNO-CCSD(T) calculation using the LED scheme. This includes geometry definition and calculation keywords. ```input ! dlpno-ccsd(t) cc-pvdz cc-pvdz/c cc-pvtz/jk rijk verytightscf TightPNO LED *xyz 0 3 C(1) 0.32786304018834 0.25137292674595 0.32985672433579 H(1) 0.78308855251826 -0.37244139824620 -0.42204823336026 H(1) -0.19639272865450 1.19309490346756 0.33713773666060 O(2) -1.47005964014997 -1.60804001777555 1.84974416203666 H(2) -0.89305417808014 -1.00736849071095 1.35216686141176 H(2) -1.02515061661047 -1.73931270222718 2.69260529998224 * ``` -------------------------------- ### Multi-Layer IP-EOM-DLPNO-CCSD Input Example Source: https://www.faccts.de/docs/orca/6.1/manual/_sources/contents/modelchemistries/mdci.md.txt Example input file for a multi-layer IP-EOM-DLPNO-CCSD calculation. This setup is suitable for including environmental effects in IP calculations, treating the main fragment (e.g., thymine) at a high level and the environment (e.g., water) at an intermediate or lower level. ```orcainput ! IP-EOM-DLPNO-CCSD TightSCF NORMALPNO def2-SVP def2-SVP/C def2/J RIJCOSX %mdci nroots 4 DTOl 1e-7 NORMALPNOFragInter { 1 1} LOOSEPNOFragInter { 1 1} HFFRAGMENTINTERACTION { 2 2} end *xyz 0 1 C(1) 2.782064 -1.456235 0.000000 C(1) 1.478695 -0.729491 0.000000 C(1) 0.274461 -1.343436 0.000000 N(1) -0.914790 -0.659079 0.000000 C(1) -0.988897 0.709718 0.000000 N(1) 0.241239 1.324758 0.000000 H(1) 0.224165 2.335424 0.000000 C(1) 1.507368 0.726274 0.000000 O(1) 2.518005 1.411594 0.000000 O(1) -2.043648 1.337449 0.000000 H(1) -1.808257 -1.143873 0.000000 H(1) 0.182931 -2.420317 0.000000 H(1) 2.626386 -2.532891 0.000000 H(1) 3.370859 -1.183830 -0.874506 H(1) 3.370859 -1.183830 0.874506 O(2) -3.661424 -0.883408 0.000000 H(2) -3.462053 0.068032 0.000000 H(2) -4.615649 -0.964529 0.000000 * ``` -------------------------------- ### Basic LED Calculation Setup Source: https://www.faccts.de/docs/orca/6.1/manual/contents/spectroscopyproperties/led.html To obtain the energy decomposition, define fragments and include the `!LED` keyword in the input line along with the desired calculation method and basis sets. ```input dlpno-ccsd(t) cc-pvdz cc-pvdz/c cc-pvtz/jk LED ``` -------------------------------- ### Example Command with Modifiers and Arguments Source: https://www.faccts.de/docs/orca/6.1/manual/_sources/contents/moleculardynamics/moldyn.md.txt A concrete example showing the 'Dump' command with its arguments and modifiers 'Stride' and 'Filename'. ```orca %md Dump Position Stride 1 Filename "trajectory.xyz" end ``` -------------------------------- ### Component Syntax Example Source: https://www.faccts.de/docs/orca/6.1/manual/_sources/contents/utilitiesvisualization/property_file.md.txt Illustrates the syntax for a property component, including its name, type, and value. ```text &gradNorm [&Type "Double"] 7.6940943132805237e-02 ``` -------------------------------- ### 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, start, and end values must be integers. The loop includes the end value. ```orca For i From 1 To 10 Do Print(i); EndFor; ``` -------------------------------- ### Example XYZ file specification Source: https://www.faccts.de/docs/orca/6.1/manual/_sources/contents/essentialelements/coordinates.md.txt An example of how to specify an XYZ file with charge, multiplicity, and a specific filename. ```orca * xyzfile 1 2 mycoords.xyz ``` -------------------------------- ### Define Input Block Source: https://www.faccts.de/docs/orca/6.1/manual/contents/essentialelements/input.html Input blocks are defined by a starting '%' followed by the block name and terminated by 'end'. This example shows a basic method block. ```plaintext %method method HF END ``` -------------------------------- ### Basic Input Block Structure 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 simple method block. ```orca %method method HF END ``` -------------------------------- ### GoTo Example for ON/OFF Switch Source: https://www.faccts.de/docs/orca/6.1/manual/contents/workflowsautomatization/compound_examples.html This Compound script uses the GoTo command to efficiently toggle a switch variable between 'ON' and 'OFF' states within a loop. It prints the current state before switching. ```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 ``` -------------------------------- ### Method File Example with CPCM Solvation Source: https://www.faccts.de/docs/orca/6.1/manual/_sources/contents/spectroscopyproperties/nocv.md.txt Example of a method file content specifying a calculation method and CPCM solvation parameters. ```orca BP86 TZVP %CPCM #CPCM block epsilon 80 #Dielectric constant refrac 1.0 #Refractive index END ``` -------------------------------- ### Get Bond Distance Between Two Atoms Source: https://www.faccts.de/docs/orca/6.1/manual/contents/workflowsautomatization/compounddetails.html Calculates the distance between two specified atoms in a geometry object, returning the result in Bohrs. Atom indices start from 0. ```Python # ------------------------------------ # This is to test Geometry function # GetBondDistance # ------------------------------------ %Compound Variable dist; Geometry myGeom; New_Step !BP86 *xyz 0 1 H 0.0 0.0 0.0 H 0.0 0.0 0.8 * Step_End myGeom.Read(); #Reads teh geometry of the previous step print( " ------------------------------------------------------- "); print( " Compound Geometry functions test (GetBondDistance) "); print( " It should print 1.5118 "); print( " ------------------------------------------------------- "); print( " The distance between atom %d and atom %d is: %.4lf Bohr\n", 0, 1, myGeom.GetBondDistance(0,1)); End ``` -------------------------------- ### JSON Formats Configuration Example Source: https://www.faccts.de/docs/orca/6.1/manual/contents/utilitiesvisualization/orca_2json.html Example configuration for specifying multiple JSON output formats, including ASCII JSON, binary JSON, UBJSON, and MessagePack. ```json { "JSONFormats":["json","bson","ubjson","msgpck"] } ``` -------------------------------- ### Internal Coordinates (int) Z-matrix Example Source: https://www.faccts.de/docs/orca/6.1/manual/contents/essentialelements/coordinates.html Specifies internal coordinates using a Z-matrix format, defining bond lengths, angles, and dihedrals. Atom numbering starts from 1. ```text * int Charge Multiplicity Atom1 0 0 0 0.0 0.0 0.0 Atom2 1 0 0 R1 0.0 0.0 Atom3 1 2 0 R2 A1 0.0 Atom4 1 2 3 R3 A2 D1 . . . AtomN NA NB NC RN AN DN * ``` -------------------------------- ### Orca Input for Local Spin Analysis Source: https://www.faccts.de/docs/orca/6.1/manual/_sources/contents/spectroscopyproperties/population.md.txt This is an example Orca input file demonstrating the setup for local spin analysis. It includes basis set, SCF method, and fragmentation specifications. ```orcainput ! HF def2-SVP UHF TightSCF PModel %scf brokensym 3,3 end * xyz 0 1 N(1) 0 0 0 N(2) 0 0 1094 * ```