Dielectric Properties at MP2 and CCSD(T) level of theory

Hi NWChem Users and Developers!

I am trying to perform some test calculations using LiF as a test case. I try to calculate
the static polarizability and electric dipole moment at the MP2/cc-pVTZ and CCSD(T)/cc-pVTZ level
of theory, respectively, by requesting

property

 response 1 0.0

 dipole

end

For DFT and HF calculations the code (v6.0 by the way) produces the desired output
but for MP2 and CCSD(T) following error occurs

number of frequencies:     1

frequency in a.u.:  0.0000000E+00

Perturbing field: electric

Using Dipole Length Gauge

 movecs_read_header: failed to open ./ IERR =                    21

------------------------------------------------------------------------

hnd_vec_read: failed to read header      911

Does someone have an idea what the problem might be?

Thanks in advance

Sven

Hi Bert!

Thanks for you fast response.

I have performed some test calculations for LiF again. The geometry is optimized using the MP2 routine. For the MP2 calculations the polarizabilities are not available using the MP2 routine but the dipole moments are. The result is a dipole moment of -2.424 a.u. (called SCF+MP2 in the output file). For the same geometry the TCE single point calculation results in a value of 2.780 a.u. . The former value
is much closer to the experimental result (2.472 a.u.) obtained by Stark-modulated MW spectroscopy (J. Chem. Phys. 38 1203 1963). Therefore I wondered what the difference between the two routines might be?

Best wishes

Sven

Hi Bert!

It seems that the problem is that for mbpt2 the code is not able to do response properties or calculations for the dipole moment. I think you mentioned in your first answer in the forum that response properties are available for MBPT and CC calculations. So I am not sure if I have a mistake in my input, if the calculation is available in general. The input file for the job is:

start LiF

memory total 2500 mb

geometry

 symmetry c1

 Li 0 0 0.00

 F  0 0 1.56

end

basis spherical

 Li library cc-pvtz

 F  library cc-pvtz

end

tce

freeze core

MBPT2

io ga

2eorb

dipole

tilesize 16

end

set tce:lineresp T
set tce:afreq 0.000
set tce:respaxis T T T

mp2

 freeze core

end

task mp2 optimize
task mp2 freq numerical

task tce energy

tce

freeze core

ccsd(t)

io ga

2eorb

dipole

tilesize 16

end

task tce energy

The MP2 part is running fine and is giving the SCF and SCF+MP2 dipole moments. If you perform mbpt2 calculations in tce it does not seem to perform any calculations of the dipole moment or polarizability. Only the SCF part is given in the output (agrees with the results of the MP2 routine). On the other hand similar settings produce the desired output for CCSD(T) calculations (by the way I do not understand why the CCSD(T) results for the dipole moment or worse than the MP2 results.).

If you wish I could send you see output file.

Best wishes and thanks in advance

Sven

P.S.: Tried to email you this file but I am not sure if it worked, since a error occurred every time I tried to email. Consequently I am posting it here as well.

Sven,

This was my mistake. Response properties in TCE are only available for CCSD, CCSD(T), and CCSDT.

As to why the CCSD(T) is further away from experiment then MP2, this might be geometry dependent. Have you tried optimizing at the CCSD(T) level and to get the dipole moment there.

Bert