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| pes_generators [2023/06/16 10:24] – rauhut | pes_generators [2024/01/08 13:24] (current) – external edit 127.0.0.1 |
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| * **''VAR1D''=//variable//** The ''XSURF'' program reads the energy of electronic structure calculations from the internal Molpro variables, e.g. ''ENERGY'', ''EMP2'', $\dots$. The internal variable is specified by the keyword ''VAR1D''. The default for the ''VAR1D'' keyword is the internal variable ''ENERGY''. | * **''VAR1D''=//variable//** The ''XSURF'' program reads the energy of electronic structure calculations from the internal Molpro variables, e.g. ''ENERGY'', ''EMP2'', $\dots$. The internal variable is specified by the keyword ''VAR1D''. The default for the ''VAR1D'' keyword is the internal variable ''ENERGY''. |
| * **''VIBIRREP''=//variable//** The irreps of the vibrations within the XSURF, VSCF and VCI programs may differ from those within the FREQ program as the molecules will be be reoriented according to the conventions (see keyword ''ORIENT''). In order to use the same irreps as in the FREQ program, one may use ''VIBIRREP=Sort''. | * **''VIBIRREP''=//variable//** The irreps of the vibrations within the XSURF, VSCF and VCI programs may differ from those within the FREQ program as the molecules will be be reoriented according to the conventions (see keyword ''ORIENT''). In order to use the same irreps as in the FREQ program, one may use ''VIBIRREP=Sort''. |
| | <!-- * **''GMAT''=//n//** If the vibrational frequencies sould be computed with the Gmatrix formalism, $n$ determines the dimension of the expansion of the Wilson Gmatrix. Higher than 2 is not recommended |
| | * **''PSEUDOPOT''=//n//**. If the vibrational frequencies sould be computed with the Gmatrix formalism, $n$ determines the dimension of the expansion of the Wilson pseudopotential. Higher than 2 is not recommended--> |
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| The following example shows the input of a calculation which computes energy and dipole surfaces at the MP2/cc-pVTZ level and subsequently determines the anharmonic frequencies at the VSCF and VCI levels. Hartree-Fock calculations will not be restarted and the .log-file is directed to the scratch directory as defined by the $TMPDIR variable. | The following example shows the input of a calculation which computes energy and dipole surfaces at the MP2/cc-pVTZ level and subsequently determines the anharmonic frequencies at the VSCF and VCI levels. Hartree-Fock calculations will not be restarted and the .log-file is directed to the scratch directory as defined by the $TMPDIR variable. |
| * **''THRLOC''=//value//** (=1.0d-6 Default) Threshold within the localization procedure. | * **''THRLOC''=//value//** (=1.0d-6 Default) Threshold within the localization procedure. |
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| ==== Scaling of individual coordinates ==== | ==== Scaling of individual normal coordinates ==== |
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| ''SCALNM'',//options// | ''SCALNM'',//options// |
| * **''SHOW''=//n//** (=0 default) Addition printing within the scaling procedure is switched on by ''SHOW=1''. | * **''SHOW''=//n//** (=0 default) Addition printing within the scaling procedure is switched on by ''SHOW=1''. |
| * **''THRSHIFT''=//value//** Threshold controlling the automated shifting of potentials as obtained from the state densities on the lhs and rhs of the potentials. The default is given as ''THRSHIFT=0.05''. | * **''THRSHIFT''=//value//** Threshold controlling the automated shifting of potentials as obtained from the state densities on the lhs and rhs of the potentials. The default is given as ''THRSHIFT=0.05''. |
| | |
| | <!--==== Scaling of individual internal coordinates ==== |
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| | ''SCALIC'',//options// |
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| | The ''SCALIC'' directive allows for the scaling with respect to the individual internal coordinates or an automated scaling of all of them. |
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| | === Options === |
| | |
| | * **''AUTO''=//on / off//** ''AUTO''=//on// (default) switches on an automatic scaling procedure of the potential in order to determine meaningful elongations and ''SHIFT'' values with respect to all coordinates, i.e. for each normal mode an optimized scaling parameter ''SFAC'' and ''SHIFT'' parameter will be determined. Usually this results in an increased number of 1D grid points. The ''AUTO'' keyword intrinsically depends on the thresholds and parameters, which can be controlled by the keywords ''THRSHIFT'', ''ITMAX'', ''LEVMAX'', ''DENSMAX'', and ''DENSMIN''. |
| | * **''DENSMAX''=//value//** (=1.d-2 default) Threshold for the maximum vibrational density on the edges of the potential needed for the automated upscaling of the potentials (see keyword ''AUTO''). |
| | * **''DENSMIN''=//value//** (=1.d-4 default) Threshold for the minimum vibrational density on the edges of the potential needed for the automated downscaling of the potentials (see keyword ''AUTO''). |
| | * **''LEVMAX''=//n//** Maximum number of vibrational states to be included for controlling the automated scaling and shifting procedure. The default is set to 5. This value should support subsequent VCI calculations. |
| | * **''MIN(n)''=//value//** Defines the minimum $value$ of coordinate $n$. |
| | * **''MAX(n)''=//value//** Defines the maximum $value$ of coordinate $n$. |
| | --> |
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| ==== Fit Functions ==== | ==== Fit Functions ==== |
| * **''NEL''=//n//** Number of data to be read in for one point. | * **''NEL''=//n//** Number of data to be read in for one point. |
| * **''VARx''=//variable//** (x=number) Name of the variable, which shall be read from the input file. | * **''VARx''=//variable//** (x=number) Name of the variable, which shall be read from the input file. |
| | <!--==== Internal Coordinates ==== |
| | |
| | ''INTC'',//options// |
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| | The ''XSURF'' programs allows to compute the desired surfaces with the use of internal coordinates. |
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| | === Options === |
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| | * **''TYPE''=//n//** Type of internal Coordinate. **n=** |
| | * 1: Zmatrix coordinates (need to be provided via the Input geometry) |
| | * 2: Delocalised internal coordinates |
| | * 3: Natural internal coordinates |
| | * **''ECKART''=//n//** If $n=1$, the geometry is rotated according to the eckart conditions which is recommended for the use of other properties than the energy |
| | * **''NDIMGMAT''=//n//** Determines the order of the expansion of the Wilson G matrix. Higher than dimension 2 is not recommended |
| | * **''NDIMVG''=//n//**. Determines the order of the expansion of the PSeudopotential. Higher than the dimension 2 is not recommended |
| | * **''RADII''=//x//** $x$ is the threshold for detecting a bon between two atoms |
| | * **''CUTOFF''=//x//** $x$ is the threshold for detecting clusters (not useable currently) |
| | * **''THRGEOM''=//x//** Threshold to determine if the geometry is converged |
| | * **''ITMAX''=//n//** Defines the maximum number of iteration when elongate the geometries |
| | * **''PSCRLAB''=//label//** Defines a label for precomputing the surface to determine a first scaling |
| | * **''VAM''=//n//** If $n=1$, rovibrational coupling is considered when the G-matrix is computed--> |
| ==== Recommendations ==== | ==== Recommendations ==== |
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