### Geometry Optimization Setup Source: https://gaussian.com/afc Sets up a geometry optimization calculation using the UB3LYP/3-21G model chemistry with a specified high spin state. This is the initial step for finding the optimal structure. ```text UB3LYP/3-21G Spin to 11-et ``` -------------------------------- ### Set Command for Starting Network Parallel Workers Source: https://gaussian.com/options Use the -s option to specify the command for starting workers in network parallel jobs. Common commands include 'ssh' or 'rsh'. ```bash -s=ssh ``` -------------------------------- ### Fragment Guess Job Setup Source: https://gaussian.com/afc Sets up a fragment guess job using Gaussian 16's fragment guess features. Ensure 'Use fragment (atom group) for generating guess' and 'Only do guess (no SCF)' are checked. ```text %oldchk=afc4 %chk=afc5 # ub3lyp/3-21g guess=(fragment=4,only) ``` -------------------------------- ### Stability Calculation from Closed-Shell Singlet Source: https://gaussian.com/afc Performs a Stable=Opt calculation starting from a closed-shell singlet. This is used as a check to compare energies and confirm the antiferromagnetic state is the ground state. ```text %oldchk=afc5 %chk=afc7 #p rb3lyp/3-21g geom=allcheck stable=opt ``` -------------------------------- ### GaussView 6 BibTeX Citation Source: https://gaussian.com/citation Use this BibTeX entry as a starting point for citing GaussView Version 6. Ensure to replace '6' with the actual revision identifier if a different version is used. ```bibtex @misc{gv6, author={Roy Dennington and Todd A. Keith and John M. Millam}, title={GaussView {V}ersion {6}}, note={Semichem Inc. Shawnee Mission KS}, year={2019} } ``` -------------------------------- ### Specify Complete Route for Job Source: https://gaussian.com/options The -x option allows you to provide the complete route for the job directly on the command line, bypassing the need to read it from the input file. ```bash -x="# b3lyp/6-31G(d) opt freq" ``` -------------------------------- ### List Hostnames for Network Parallel Jobs Source: https://gaussian.com/options The -w option specifies a list of hostnames for network parallel jobs. This allows Gaussian to distribute computations across multiple machines. ```bash -w="apple,banana,cherry" ``` -------------------------------- ### Read Input from Existing Checkpoint File Source: https://gaussian.com/options The -ic option allows you to read input from an existing checkpoint file, enabling continuation of previous calculations. ```bash -ic=job6 ``` -------------------------------- ### Specify Read-Write File Source: https://gaussian.com/options Use the -z option to specify a read-write file for Gaussian jobs. This file can be used for temporary storage or specific I/O operations. ```bash -z=/scratch2/fox7.rwf ``` -------------------------------- ### Specify Output Raw Matrix Element File Source: https://gaussian.com/options The -or option specifies an output raw matrix element file. This saves matrix data in a direct, unformatted representation. ```bash -or=job7_raw ``` -------------------------------- ### Single Point Energy Calculation with Optimization and Single Point Source: https://gaussian.com/capabilities?tabid=0 Requests a geometry optimization at a specified model chemistry followed by a single point energy calculation at the optimized geometry. The Opt keyword is optional as it's the default behavior for this syntax. ```route section # CCSD/6-31G(d)//B3LYP/6-31G(d) ``` -------------------------------- ### Mulliken Atomic Spin Densities Source: https://gaussian.com/afc Displays the Mulliken atomic spin densities calculated for the antiferromagnetic state. This output helps in verifying the spin distribution on the metal centers and ligands. ```text Mulliken atomic spin densities: 1 1 Mn 3.931283 2 O -0.000000 3 O -0.000000 4 Mn -3.931283 5 H 0.005293 ... ``` -------------------------------- ### Define Processor/Core List for Parallel Jobs Source: https://gaussian.com/options Use the -c option to specify the list of processors or cores for multiprocessor parallel jobs. This enables efficient utilization of multi-core systems. ```bash -c="0-31" ``` -------------------------------- ### Read Input from Matrix Element File Source: https://gaussian.com/options Use the -im option to read input from a matrix element file. This is useful for providing specific matrix data to the calculation. ```bash -im=fox7.dat ``` -------------------------------- ### Read Input from 8-byte Integer Matrix Element File Source: https://gaussian.com/options Use the -im8 option to read input from a matrix element file using 8-byte integers. This is suitable for larger matrix data. ```bash -im8=fox7 ``` -------------------------------- ### Specify Output Matrix Element File Source: https://gaussian.com/options Use the -om option to specify an output matrix element file. This allows you to save computed matrix data. ```bash -om=job16new_mat ``` -------------------------------- ### Specify Output 8-byte Integer Matrix Element File Source: https://gaussian.com/options Use the -om8 option to specify an output matrix element file using 8-byte integers. This is suitable for saving larger matrix data. ```bash -om8=job64mat ``` -------------------------------- ### Read Input from Raw Matrix Element File Source: https://gaussian.com/options The -ir option reads input from a raw matrix element file. This is a direct, unformatted representation of matrix data. ```bash -ir=job6 ``` -------------------------------- ### Specify Memory Amount for Gaussian Jobs Source: https://gaussian.com/options The -m option allows you to set the memory amount for Gaussian jobs. Ensure the value is appropriate for your system's resources. ```bash -m=200GB ``` -------------------------------- ### Specify GPUs and Cores for GPU Parallel Jobs Source: https://gaussian.com/options The -g option is used to list GPUs and their associated cores for GPU parallel jobs. This is crucial for accelerating computations on systems with GPUs. ```bash -g="0-8=0-6,31,32" ``` -------------------------------- ### Specify Output 8-byte Integer Raw Matrix Element File Source: https://gaussian.com/options The -or8 option specifies an output raw matrix element file using 8-byte integers. This is suitable for saving larger raw matrix data. ```bash -or8=proteins_rawdat ``` -------------------------------- ### Read Input from 8-byte Integer Raw Matrix Element File Source: https://gaussian.com/options The -ir8 option reads input from a raw matrix element file using 8-byte integers. This is suitable for larger raw matrix data. ```bash -ir8=job7 ``` -------------------------------- ### Set Default Keyword List for Route Section Source: https://gaussian.com/options Use the -r option to specify a default list of keywords for the route section of Gaussian jobs. This is useful for setting common calculation parameters. ```bash -r="Int=SuperFine Freq=HPModes" ``` -------------------------------- ### Read Input from 4-byte Integer Matrix Element File Source: https://gaussian.com/options The -im4 option reads input from a matrix element file using 4-byte integers. This is a specialized format for matrix data. ```bash -im4=fox12 ``` -------------------------------- ### Specify Output 4-byte Integer Raw Matrix Element File Source: https://gaussian.com/options Use the -or4 option to specify an output raw matrix element file using 4-byte integers. This is a specialized format for saving raw matrix data. ```bash -or4=proteins_rawdat ``` -------------------------------- ### Read Input from 4-byte Integer Raw Matrix Element File Source: https://gaussian.com/options Use the -ir4 option to read input from a raw matrix element file using 4-byte integers. This is a specialized format for raw matrix data. ```bash -ir4=job27 ``` -------------------------------- ### Specify Output 4-byte Integer Matrix Element File Source: https://gaussian.com/options The -om4 option specifies an output matrix element file using 4-byte integers. This is a specialized format for saving matrix data. ```bash -om4=job32mat ``` -------------------------------- ### Specify Checkpoint File Source: https://gaussian.com/options Use the -y option to specify the checkpoint file for Gaussian jobs. This file stores intermediate results and can be used for restarting calculations. ```bash -y="$HOME/project3/gfp.chk" ``` -------------------------------- ### Generate Formatted Checkpoint File Source: https://gaussian.com/options The -fchk option generates a formatted checkpoint file alongside the binary one and updates it as the checkpoint file is updated. This provides a human-readable checkpoint file. ```bash -fchk=/plots/job8.fchk ``` -------------------------------- ### Specifying a Density Fitting Basis Set Source: https://gaussian.com/basissets?tabid=0 Use slashes to separate the method, basis set, and fitting set when specifying a density fitting basis set in the model chemistry. ```text # BLYP/TZVP/TZVPFit ``` -------------------------------- ### Optimize High Spin Geometry Source: https://gaussian.com/afc Used to reoptimize the high spin geometry using a previously found high spin wavefunction. Ensure the %oldchk file is correctly specified. ```text %oldchk=afc2 %chk=afc3 #p b3lyp/3-21g opt geom=allcheck guess=read ``` -------------------------------- ### Wavefunction Stability Check Source: https://gaussian.com/afc Checks the stability of the wavefunction at the final geometry obtained from a previous optimization. It uses the checkpoint file from the previous job as input and specifies 'stable=opt' to find a lower energy state if the current wavefunction is unstable. ```gaussian %oldchk=afc1 %chk=afc2 #p b3lyp/3-21g guess=read geom=check stable=opt Mn2O2(NH3)8 High Spin (antiferromagnetic coupling) 0,11 ``` -------------------------------- ### UGBS Basis Set with Polarization Functions Source: https://gaussian.com/basissets?tabid=0 Specifies the universal Gaussian basis set (UGBS) with optional polarization functions. The 'n' denotes the number of polarization functions, 'V' indicates valence functions, and 'O' indicates core functions. ```text UGBSnP|V|O ``` -------------------------------- ### 13C NMR Estimation Protocol Source: https://gaussian.com/nmrcomp This snippet shows the textual output from a CS ChemNMR Pro calculation on taxol, illustrating the protocol for estimating 13C NMR chemical shifts relative to TMS. ```text Protocol of the 13C NMR Estimation Node Estim. Base Incr. Comment (ppm rel. to TMS) C 138.5 123.3 1-ethylene -8.9 1 -C-C-C-C -7.4 1 -C 17.3 1 -C-C-C-C 14.2 1 -C-O ``` -------------------------------- ### Check Stability of High-Spin Wavefunction Source: https://gaussian.com/afc Performs a stability calculation on the high-spin wavefunction at the final geometry. This confirms the stability of the optimized state. ```text %oldchk=afc3 %chk=afc4 # b3lyp/3-21g guess=read geom=allcheck stable=opt ``` -------------------------------- ### Stability Calculation for Antiferromagnetic Wavefunction Source: https://gaussian.com/afc Performs a stability calculation on the resulting wavefunction from the fragment guess job. This confirms the stability of the antiferromagnetic state. ```text %oldchk=afc5 %chk=afc6 # ub3lyp/3-21g scf=nosymm guess=read geom=allcheck stable=opt ``` -------------------------------- ### Gaussian 16 BibTeX Citation Source: https://gaussian.com/citation Use this BibTeX entry for academic citations of Gaussian 16. Ensure to replace 'Revision C.01' with the specific revision used. ```bibtex @misc{g16, author={M. J. Frisch and G. W. Trucks and H. B. Schlegel and G. E. Scuseria and M. A. Robb and J. R. Cheeseman and G. Scalmani and V. Barone and G. A. Petersson and H. Nakatsuji and X. Li and M. Caricato and A. V. Marenich and J. Bloino and B. G. Janesko and R. Gomperts and B. Mennucci and H. P. Hratchian and J. V. Ortiz and A. F. Izmaylov and J. L. Sonnenberg and D. Williams-Young and F. Ding and F. Lipparini and F. Egidi and J. Goings and B. Peng and A. Petrone and T. Henderson and D. Ranasinghe and V. G. Zakrzewski and J. Gao and N. Rega and G. Zheng and W. Liang and M. Hada and M. Ehara and K. Toyota and R. Fukuda and J. Hasegawa and M. Ishida and T. Nakajima and Y. Honda and O. Kitao and H. Nakai and T. Vreven and K. Throssell and Montgomery, {Jr.}, J. A. and J. E. Peralta and F. Ogliaro and M. J. Bearpark and J. J. Heyd and E. N. Brothers and K. N. Kudin and V. N. Staroverov and T. A. Keith and R. Kobayashi and J. Normand and K. Raghavachari and A. P. Rendell and J. C. Burant and S. S. Iyengar and J. Tomasi and M. Cossi and J. M. Millam and M. Klene and C. Adamo and R. Cammi and J. W. Ochterski and R. L. Martin and K. Morokuma and O. Farkas and J. B. Foresman and D. J. Fox}, title={Gaussian˜16 {R}evision {C}.01}, year={2016}, note={Gaussian Inc. Wallingford CT} } ``` === COMPLETE CONTENT === This response contains all available snippets from this library. No additional content exists. Do not make further requests.