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Typo in integral definition for .EFGCAR?

Posted: 23 Mar 2017, 02:14
by ejberquist
I think there might be a typo in the equation for the Cartesian electric field gradient integrals for

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.EFGCAR
, and that the prefactor of (1/3) should not be present.

Ignoring symmetry and their prefactors, each component of the EFG integrals should be the same as for the spin-dipole integrals. That is, when I divide the matrix representation of

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XXEFG011
by the matrix representation of

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SD 001 x
, for example, each entry should be 1 after the prefactors are divided out as well. However, this is only true when (g_e/2) is divided out of the SD integrals, and not (1/3) from the EFG integrals.

I did not check the spherical EFG integrals.

Re: Typo in integral definition for .EFGCAR?

Posted: 23 Mar 2017, 13:17
by olav
Hi

As a general rule there is no right or wrong when it comes to integral prefactors as long as they are known and documented and properly accounted for when the final property is calculated and reported.

I don't know about the specifics of this case. You are right that taking the gradient of the electric field from a point charge does not give such a factor of 1/3. The author of the code might nevertheless have had a reason for putting it on the integral rather than somewhere else. I could also be a typo in the documentation as you say, but not necessarily.

Regards
Olav