Vibrational analysis: *VIBANA

 

Directives controlling the calculation of harmonic vibrational  frequencies appear in the *VIBANA section, as well as properties depending on a normal coordinate analysis or vibrational frequencies. Such properties include in the present version of the program: Vibrational Circular Dichroism (VCD), Raman intensities, and Raman Optical Activity (ROA)      .

.HESFIL  

Read the molecular Hessian  from the file DALTON.HES. This file may have been made in an earlier calculation using the keyword .HESPUN  , or constructed from a calculation with the Gaussian94 program and converted to DALTON\ format using the FChk2HES.f program. Useful in VCD and VROA analyses    .

.HESPUN  

Write the molecular Hessian  to the file DALTON.HES for use as starting Hessian in first-order  geometry optimizations (see keyword .HESFIL   in the *MINIMIZE   input module), or for later use in a vibrational analysis (see keyword .HESFIL   in this input module) .

.NOCID  

Do not calculate the Circular Intensity Differentials   (CIDs) as defined by Barron [82], but instead print the chirality  numbers defined by Hug [83] in calculation of vibrational Raman Optical Activity (VROA)  .

.ISOTOP  

READ (LUCMD,*) NISOTP, NATM
DO 305 ICOUNT = 1, NISOTP
   READ (LUCMD,*) (ISOTP(ICOUNT,N), N = 1, NATM)
END DO

Read in the number of different isotopically  substituted species NISOTP fore which we will do a vibrational analysis. The isotopic species containing only the most abundant isotopes is always calculated.

NATM is the total number of atoms in the molecules (see discussion in Section . For each isotopic species, the isotope for each atom in the molecule is read in. A 1 denotes the most abundant isotope, a 2 the second-most abundant isotope and so on.

.PRINT  

READ (LUCMD,*) PRINT

Set the print level in the vibrational  analysis of the molecule. Read one more line containing print level. Default value is the value of IPRDEF from the general input module.

.SKIP  

Skip the analysis of the vibrational frequencies and modes of the molecule.