Calculation of dipole moments

Posted by Andy Kerridge on September 29, 2011 at 18:49:43:

Hi,

I'm trying to calculate the dipole moment of NiH, which has been done previously using CASSCF (J. Chem. Phys. 101:4893, 1994). My CASSCF value is approximately 3D, in general agreement with the CASSCF value quoted in the paper of 3.1D. However, in the paper a refined value of 2.65 is obtained using CASPT2. My CASPT2 calculated value is essentially the same as my CASSCF one, in fact a little larger. I am using the DENSITY keyword in CASPT2, as recommended in the manual. Can someone explain why do I not see an improvement in my calculated value? I notice that the dipole moment is calculated using a perturbative approach in the paper, but my output gives an expectation value for the dipole moment. Is this the cause of the difference? I understand that FFPT can be used in order to obtain a perturbative result, but can anyone tell me how the calculation is actually performed?

Regards,

Andy

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Re: Calculation of dipole moments Steven 09:32:43 9/19/12 (0)

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if B is 1s22s22p1, what is Li?

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: Hi, : I'm trying to calculate the dipole moment of NiH, which has been done previously using CASSCF (J. Chem. Phys. 101:4893, 1994). My CASSCF value is approximately 3D, in general agreement with the CASSCF value quoted in the paper of 3.1D. However, in the paper a refined value of 2.65 is obtained using CASPT2. My CASPT2 calculated value is essentially the same as my CASSCF one, in fact a little larger. I am using the DENSITY keyword in CASPT2, as recommended in the manual. Can someone explain why do I not see an improvement in my calculated value? I notice that the dipole moment is calculated using a perturbative approach in the paper, but my output gives an expectation value for the dipole moment. Is this the cause of the difference? I understand that FFPT can be used in order to obtain a perturbative result, but can anyone tell me how the calculation is actually performed? : Regards, : Andy

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