CC Vibrational Frequencies

[benmck95]

Hello,

I am new to Dalton(2018.0) and I am trying to calculate the vibrational frequencies with CC2. I have searched the forums and manual for a possible answer but couldn't find any. Im aware that CC2 requires numerical gradients and the calculation doesn't appear to end with an error and I can not find the frequencies in the .out file.

Thanks for any help in advance, hopefully I haven't overlooked something simple.

.dal INPUT:

**DALTON INPUT
.NMDDRV
**INTEGRAL
.DIPLEN
.DEROVL
.DERHAM
**WAVE FUNCTIONS
.CC
*CC INPUT
.CC2
**NMDDRV
.VIBANA
**END OF DALTON INPUT

[magnus]

Sorry for late reply. I only just now saw your post. I'm far from an expert in this part of the program, but I believe you need to use an input like the following:

Code: Select all

**DALTON INPUT
.NMDDRV
**NMDDRV
.DORDR
 2  0
.HARMONIC
**INTEGRALS
.DIPLEN
.DEROVL
.DERHAM
**WAVE FUNCTIONS
.CC
*CC INPUT
.CC2
**END OF DALTON INPUT

[magnus]

There are also analytic gradients and geometry optimizations available for some CC methods, among others CC2, so you should also be able to use the following input as well:

Code: Select all

**DALTON INPUT
.NMDDRV
**NMDDRV
.DORDR
 1 1
.HARMONIC
**INTEGRALS
.DIPLEN
.DEROVL
.DERHAM
**WAVE FUNCTIONS
.CC
*CC INPUT
.CC2
*DERIVATIVES
**END OF DALTON INPUT