# Differences

This shows you the differences between two versions of the page.

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pes_generators [2020/06/12 13:08] qianli [Options] |
pes_generators [2022/02/28 08:35] (current) rauhutmoschneide [Scaling of individual coordinates] |
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The following //options// are available: | The following //options// are available: | ||

+ | * **'' | ||

+ | * **'' | ||

+ | * **'' | ||

+ | * **'' | ||

+ | * **'' | ||

+ | * **'' | ||

+ | * **'' | ||

+ | * **'' | ||

+ | * **'' | ||

+ | * **'' | ||

- | '' | ||

- | The keyword '' | ||

- | |||

- | '' | ||

- | Based on a coarse grid of //ab initio// points a fine grid will be generated from automated interpolation techniques. The keyword '' | ||

^Grid points | ^Grid points | ||

|Surface extension | |Surface extension | ||

- | ''VAR1D''variable// | + | * **''ORIENT''** Allows to specify a certain orientation of the molecule. With ''=//yes//'' (Default) the orientation is choosed automatically according to the asymmetric parameter of the molecule. To choose a certain orientation, ''ORIENT=//'' need to be set. X represents a number from 1 to 3 (in arabic or roman letters), and C need to be set to **r** or **l**. For example, ''ORIENT=//IIl//'' orientates the molecule according to the **IIl** convention. ''ORIENT=//old//'' does not rotate the molecule at all. |

- | The ''SURF''the energy of electronic structure calculations from the internal Molpro variables, e.g. '', ''EMP2'', $\dots$. The internal variable is specified by the keyword ''example shown above, ''VAR1D=ENERGY'' would read the CCSD energy, while ''VAR1D=EMP2'' would read the MP2 energy, which is a byproduct of the CCSD calculation. The default for the ''VAR1D'' keyword is the internal variable ''ENERGY'' | + | * **''PLOT''=//''PLOT''n// plots all //n//D surfaces and a corresponding Gnuplot script in a separate subdirectory (''plots1'') in the //to allow for visualization of the computed //n//D surfaces. E.g. the command ".gnu" in the ''plots1'' directory produces .eps files for all 1D surfaces. Default: ''PLOT=0'' |

- | | + | * **''SADDLE''** Standard ''the reference structure to be a (local) minimum on the PES, i.e. ''SADDLE=0'' (default). Alternatively,is recommended for the calculation of double-minimum potentials. This situation is not recognized automatically and thus requires the keyword ''SADDLE=1''. Within ''. |

- | ''''variable// | + | * **''** The extension of the potential energy surfaces is determined from Gauss-Hermite quadrature points. Using a fine grid '' |

- | Symmetry within electronic structure calculations can be exploited by the keyword ''SYM=Auto''. Usually this leads to significant time savings. By default this symmetry recognition is switched off as certain calculations may cause some trouble (e.g. local correlation methods). Symmetry in electronic structure calculations may not be mistaken by the symmetry of the mode-coupling terms (see keyword ''MPG''). Once ''SYM=Auto'' is used, it is advisable to insert an ''. | + | * **''** As the number of 3D and 4D surfaces can increase very rapidly, there exists the possibility to neglect unimportant 3D and 4D surfaces by the keywords '' |

- | | + | * **''SYM''variable//** Symmetry within electronic structure calculations can be exploited by the keyword ''SYM=Auto''. Usually this leads to significant time savings. By default this symmetry recognition is switched off as certain calculations may cause some trouble (e.g. local correlation methods). Symmetry in electronic structure calculations may not be mistaken by the symmetry of the mode-coupling terms (see keyword ''MPG''). Once ''used, it is advisable to insert an ''INT'' card prior to the call of the Hartree-Fock program. |

- | ''MPG'' | + | * **''THRFIT''value//** The iterative algorithm for generating potential energy surfaces is based on a successive increase of interpolation points. The iterations are terminated once the interpolation of two subsequent iteration steps became stable. The convergence threshold can be changed by the keyword ''THRFIT=f''There is currently just one control variable for the different 1D, 2D, 3D, and 4D iterations. The 4 thresholds are different but depend on each other. Consequently, changing the default value (''THRFIT=4.0d-2''will change all thresholds simultaneously which keeps the calculation balanced. |

- | Symmetry of the normal modes is recognized by the program automatically. Only Abelian point groups can be handled at the moment. Symmetry of the modes will be determined even if the ''NOSYM'' keyword is used in the electronic structure calculations. In certain cases numerical noise can be very high and thus prohibits a correct determination of the symmetry labels. Symmetry can be switched off by using ''MPG=1'' | + | * **''** ''. Note that, within ''. |

- | | + | * **''** Once the Mrcc program of M. Kallay or the Gecco program of A. Köhn is used for determining individual grid points, the option '' |

- | '' | + | * **''VAR1D''variable//** The ''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''Within the example shown above, ''VAR1D=ENERGY'' would read the CCSD energy, while ''VAR1D=EMP2'' would read the MP2 energy, which is a byproduct of the CCSD calculation. The default for the ''VAR1D'''' |

- | The extension of the potential energy surfaces is determined from Gauss-Hermite quadrature points. Using a fine grid '' | + | * **''VRC''** Once the keyword ''VRC=1'' is provided, the ''SURF'' program will also compute the vibrational-rotational coupling surfaces and thus increases the number of degrees of freedom to 3N-3. Vibrational-rotational coupling surfaces can only be used within the ''PESTRANS'' program (see below), but will be neglected in any VSCF or VCI calculations. |

- | | + | |

- | '' | + | |

- | The iterative algorithm for generating potential energy surfaces is based on a successive increase of interpolation points. The iterations are terminated once the interpolation of two subsequent iteration steps became stable. The convergence threshold can be changed by the keyword '' | + | |

- | | + | |

- | '' | + | |

- | The maximum order of the polynomials used for fitting within the iterative interpolation scheme can be controlled by the keywords '' | + | |

- | | + | |

- | '' | + | |

- | The minimum number of coarse grid points can be controlled by the keywords '' | + | |

- | | + | |

- | '' | + | |

- | The maximum number of coarse grid points can be controlled by the keywords '' | + | |

- | | + | |

- | '' | + | |

- | Outer regions of the potential energy surfaces may be determined by extrapolation rather than interpolation schemes. By default extrapolation is switched off, i.e. '' | + | |

- | | + | |

- | '' | + | |

- | As the number of 3D and 4D surfaces can increase very rapidly, there exists the possibility to neglect unimportant 3D and 4D surfaces by the keywords '' | + | |

- | | + | |

- | ''VRC''n// | + | |

- | Once the keyword ''VRC=1''provided, the ''SURF'' program will also compute the vibrational-rotational coupling surfaces and thus increases the number of degrees of freedom to 3N-3. Vibrational-rotational coupling surfaces can only be used within the ''PESTRANS''(see below), but will be neglected in any VSCF or VCI calculations. | + | |

- | | + | |

- | ''BATCH3D''n// | + | |

- | After calculating a number of grid points within the iterative interpolation scheme the convergence of the individual surfaces will be checked and, if provided by the keyword ''DUMP'', dumped to disk. This leads typically to 3-5 iterations and thus the same number of restart points within the calculation of the 1D, 2D, ... surfaces. As the number of 3D and 4D terms can be very large this is not sufficient in these cases. Therefore, the lists of 3D and 4D terms is cut into batches which will be processed subsequently. ''each batch. By default '', e.g. ''the number of restart points on cost of the efficiency of the parallelization. | + | |

- | | + | |

- | ''''//n// | + | |

- | Standard ''. ''SADDLE=0''). Alternatively,which is recommended for the calculation of double-minimum potentials. This situation is not recognized automatically and thus requires the keyword '' | + | |

- | + | ||

- | '' | + | |

- | '' | + | |

- | | + | |

- | '' | + | |

- | Once the Mrcc program of M. Kallay is used for determining individual grid points, the option '' | + | |

- | | + | |

- | ''DELLOG''n// | + | |

- | For large molecules or in the case of modelling the 3D and 4D terms, the .log-file may become huge. First of all the .log-file can be directed to scratch within the electronic structure program, i.e. ''logfile'',scratch''option ''DELLOG=1'' always truncates the .log-file in a way that it contains only the very last energy calculation. Default: ''DELLOG=0''. | + | |

- | | + | |

- | ''''//n// | + | |

- | ''INFO=1''a list of the values of all relevant program parameters (options). Default: ''INFO=0'' | + | |

- | | + | |

- | ''PLOT'' | + | |

- | ''PLOT''=//n// plots all //n//D surfaces and a corresponding Gnuplot script in a separate subdirectory (''plots1'') in the //home//-directory in order to allow for visualization of the computed //surfaces. E.g. the command ".gnu" in the ''plots1'''' | + | |

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. | ||

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'' | '' | ||

- | The level of the electronic structure calculations can be changed for the different $i$-body terms in the expansion of the potential. As a consequence, | + | The level of the electronic structure calculations can be changed for the different $i$-body terms in the expansion of the potential. As a consequence,(this restriction is lifted in the ''. |

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Dipole surfaces can be computed for all those methods for which analytical gradients are available in Molpro. For all methods except Hartree-Fock this requires the keyword '' | Dipole surfaces can be computed for all those methods for which analytical gradients are available in Molpro. For all methods except Hartree-Fock this requires the keyword '' | ||

- | Allows to switch between the different dipole surface calculations.=0 switches off all dipole calculations. '' | + | * **''Allows to switch between the different dipole surface calculations.=0 switches off all dipole calculations. '' |

- | | + | * **''NDIMDIP''//This denotes the term after which the $n$-body expansion of the dipole surfaces is truncated. The default is set to 3. Note that '' |

- | By default (''POLAR''0) Raman intensities will not be computed. '' | + | * **''This variable denotes the term after which the $n$-body expansion of the polarizability tensor surfaces is truncated. The default is set to 2. Note that '' |

- | | + | * **'' |

- | This denotes the term after which the $n$-body expansion of the dipole surfaces is truncated. The default is set to 3. Note that '' | + | * **''Variable which is used for the $x$ direction of the dipole moment for 1D surfaces. |

- | | + | * **''Variable which is used for the $y$ direction of the dipole moment for 1D surfaces. |

- | This variable denotes the term after which the $n$-body expansion of the polarizability tensor surfaces is truncated. The default is set to 2. Note that '' | + | * **''Variable which is used for the $z$ direction of the dipole moment for 1D surfaces. |

- | + | * **''Variable which is used for the $xx$ component of the polarizability tensor for 1D surfaces. | |

- | Variable which is used for the $x$ direction of the dipole moment for 1D surfaces. | + | * **''Variable which is used for the $yy$ component of the polarizability tensor for 1D surfaces. |

- | | + | * **''Variable which is used for the $zz$ component of the polarizability tensor for 1D surfaces. |

- | Variable which is used for the $y$ direction of the dipole moment for 1D surfaces. | + | * **''Variable which is used for the $xy$ component of the polarizability tensor for 1D surfaces. |

- | | + | * **''Variable which is used for the $xz$ component of the polarizability tensor for 1D surfaces. |

- | Variable which is used for the $z$ direction of the dipole moment for 1D surfaces. | + | * **''Variable which is used for the $yz$ component of the polarizability tensor for 1D surfaces. |

- | | + | |

- | Variable which is used for the $xx$ component of the polarizability tensor for 1D surfaces. | + | |

- | | + | |

- | Variable which is used for the $yy$ component of the polarizability tensor for 1D surfaces. | + | |

- | | + | |

- | Variable which is used for the $zz$ component of the polarizability tensor for 1D surfaces. | + | |

- | | + | |

- | Variable which is used for the $xy$ component of the polarizability tensor for 1D surfaces. | + | |

- | | + | |

- | Variable which is used for the $xz$ component of the polarizability tensor for 1D surfaces. | + | |

- | | + | |

- | Variable which is used for the $yz$ component of the polarizability tensor for 1D surfaces. | + | |

The higher order terms VARDIP// | The higher order terms VARDIP// | ||

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'' | '' | ||

- | The '' | + | The ''. Within the ''. |

* **'' | * **'' | ||

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'' | '' | ||

- | The ''. Using an angle of 45$^o$ between the degenerate modes of non-Abelian molecules avoids symmetry breaking in the subsequent ''. | + | The '' |

- | * **'' | ||

* **'' | * **'' | ||

* **'' | * **'' | ||

+ | * **'' | ||

* **'' | * **'' | ||

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The '' | The '' | ||

+ | * **'' | ||

+ | * **'' | ||

+ | * **'' | ||

+ | * **'' | ||

+ | * **'' | ||

* **'' | * **'' | ||

* **'' | * **'' | ||

* **'' | * **'' | ||

- | * **'' | ||

- | * **'' | ||

* **'' | * **'' | ||

- | * **'' | ||

- | * **'' | ||

- | * **'' | ||

==== Deleting individual surfaces ==== | ==== Deleting individual surfaces ==== | ||

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Within the framework of multi-level calculations (see the directive '' | Within the framework of multi-level calculations (see the directive '' | ||

- | * **'' | ||

* **'' | * **'' | ||

+ | * **'' | ||

The following example shows the input for a surface calculation in which the 3D terms will be modeled. | The following example shows the input for a surface calculation in which the 3D terms will be modeled. | ||

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- | [\tt Problem:] | + | **Problem:** |

The Surf calculation crashes with an error message like | The Surf calculation crashes with an error message like | ||

< | < | ||

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| | ||

</ | </ | ||

- | [\tt Solution:] | + | |

+ | **Solution:** | ||

The program has problems in the symmetry conversion when restarting a Hartree-Fock calculation from the reference calculation at the equilibrium geometry. You need to start the Hartree-Fock calculations independently by using the keywords '' | The program has problems in the symmetry conversion when restarting a Hartree-Fock calculation from the reference calculation at the equilibrium geometry. You need to start the Hartree-Fock calculations independently by using the keywords '' | ||

- | [\tt Problem:] | + | **Problem:** |

In parallel calculations (mppx) the CPU-time of a '' | In parallel calculations (mppx) the CPU-time of a '' | ||

- | [\tt Solution:] | + | |

+ | **Solution:** | ||

There may be two reasons for this: (1) Usually a '' | There may be two reasons for this: (1) Usually a '' | ||

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'' | '' | ||

- | The ''of the old '' | + | The ''to the old ''The '' |

+ | B. Ziegler, G. Rauhut, //Rigorous use of symmetry within the construction of multidimensional potential energy surfaces//, [[https:// | ||

+ | B. Ziegler, G. Rauhut, //Localized Normal Coordinates in Accurate Vibrational Structure Calculations: | ||

==== Options ==== | ==== Options ==== | ||

- | * **''will automatically switched off in any Taylor expansions of the PES. | + | |

+ | * **''is automatically switched off in any Taylor expansions of the PES. | ||

+ | * **''. | ||

* **'' | * **'' | ||

* **'' | * **'' | ||

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* **'' | * **'' | ||

* **'' | * **'' | ||

- | * **''scheme can be used by the option '' | + | * **''schemes can be used by the option '' |

* **'' | * **'' | ||

* **'' | * **'' | ||

- | * **''0 (off) Default) By default, (pre)screening of any terms higher than 2D of the PES expansion is switched off. It can be activated by ''1. | + | * **''1 (on) Default) By default, (pre)screening of any terms higher than 2D of the PES expansion is switched on. It can be deactivated by ''0. |

* **'' | * **'' | ||

* **'' | * **'' | ||

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* **'' | * **'' | ||

* **'' | * **'' | ||

+ | * **'' | ||

+ | ==== Selection of Modes ==== | ||

+ | '' | ||

+ | |||

+ | The '' | ||

+ | |||

+ | * **'' | ||

+ | * **'' | ||

+ | * **'' | ||

+ | * **'' | ||

+ | * **'' | ||

==== Visualisation and interfaces ==== | ==== Visualisation and interfaces ==== | ||

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The '' | The '' | ||

- | * **'' | + | * **''plots1 Default) Path or name of the directory to be specified for dumping the files for visualisation. See the keyword '' |

- | * **''plots Default) Path or name of the directory to be specified for dumping the files for visualisation. See the keyword ''. | + | |

- | * **''. | + | |

* **'' | * **'' | ||

+ | * **'' | ||

+ | * **'' | ||

==== Error correction schemes ==== | ==== Error correction schemes ==== | ||

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'' | '' | ||

- | AS the '' | + | As the '' |

* **'' | * **'' | ||

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'' | '' | ||

- | Usually, the diplacements vectors of the normal coordinates are retrieved from a preceding harmonic frequency calculation called by the ''VFREF'' | + | Usually, the diplacements vectors of the normal coordinates are retrieved from a preceding harmonic frequency calculation called by the ''VFREQ'' |

* **'' | * **'' | ||

+ | * **'' | ||

+ | * **'' | ||

* **'' | * **'' | ||

- | * **'' | ||

* **'' | * **'' | ||

- | * **'' | ||

==== Linear combinations of normal coordinates ==== | ==== Linear combinations of normal coordinates ==== | ||

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By default, the '' | By default, the '' | ||

- | * **'' | ||

* **'' | * **'' | ||

- | * **''TYPE''variable//** ''(corresponds to ''=5) specifies a full quartic force field. ''-quartic force field (as used in VPT2 calculations). ''. | + | * **''POINTS''n//** (=5 Default) Number of ab initio points controlling the accuracy of the derivatives (e.g. 5-point formula). |

* **'' | * **'' | ||

+ | * **'' | ||

+ | '' | ||

+ | \\ | ||

+ | '' | ||

==== Additional properties ==== | ==== Additional properties ==== | ||

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The '' | The '' | ||

- | * **'' | ||

- | * **'' | ||

* **'' | * **'' | ||

+ | * **'' | ||

+ | * **'' | ||

==== Interface to other programs ==== | ==== Interface to other programs ==== | ||

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* **'' | * **'' | ||

* **'' | * **'' | ||

- | * **'' | ||

* **'' | * **'' | ||

* **'' | * **'' | ||

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* **'' | * **'' | ||

* **'' | * **'' | ||

+ | * **'' | ||

==== Grid computing interface ==== | ==== Grid computing interface ==== | ||

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* **'' | * **'' | ||

* **'' | * **'' | ||

+ | |||