When calculating spinrotation constants with common gauge origin the off diagonal terms are incorrect.
Calculation with london orbitals:
34.084225 20.032869 0.000000
47.343131 30.898881 0.000000
0.000000 0.000000 32.643309
Calculation with common gauge in the center of mass:
34.255338 303.963380 0.000000
575.854478 30.607068 0.000000
0.000000 0.000000 32.207030
I have used uncontracted ccpvqz basis set to get converged results for calculation with common gauge.
My guess is that the off diagonal contribution from electric field integrals have wrong sing.
I have attached all imput files.
Stano
SpinRotation constants

 Posts: 7
 Joined: 15 Nov 2013, 11:46
 First name(s): Michal
 Last name(s): Jaszunski
 Affiliation: ICHO PAN
 Country: Poland
Re: SpinRotation constants
hello,
it appears that the reported bug is related to a sign problem in the Diamagnetic contribution.
In a test H2O LondonNoLondon HF calculation I get for the first H atom:
NoLondon
Diamagnetic contribution

A 189.736232 139.393758 0.000000
B 274.103959 201.376302 0.000000
C 0.000000 0.000000 197.314587
with the signs of the offdiagonal terms reversed for the second H atom.
With the same *.mol file (thus, the same ordering of H atoms)
London calculation gives
A 189.550915 146.733765 0.000000
B 259.481844 201.027507 0.000000
C 0.000000 0.000000 196.861315
and this leads to very reasonable
Total spin rotation constants

A 32.167417 19.594557 0.000000
B 43.706389 29.313292 0.000000
whereas in the NoLondon calculation the total is close to that reported
earlier (see below) for a DFT common origin job (and the error is removed
reversing the sign, with the change of 2*139.393758)
regards,
Michal
On Sun, 25 May 2014 14:30:14 +0200, noreply@daltonprogram.org wrote:
Posted by uachstno
When calculating spinrotation constants with common gauge origin the off
diagonal terms are incorrect.
Calculation with london orbitals:
34.084225 20.032869 0.000000
47.343131 30.898881 0.000000
0.000000 0.000000 32.643309
Calculation with common gauge in the center of mass:
34.255338 303.963380 0.000000
575.854478 30.607068 0.000000
0.000000 0.000000 32.207030
I have used uncontracted ccpvqz basis set to get converged results for
calculation with common gauge.
My guess is that the off diagonal contribution from electric field
integrals have wrong sing.
I have attached all imput files.
Stano

View the first unread post:
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it appears that the reported bug is related to a sign problem in the Diamagnetic contribution.
In a test H2O LondonNoLondon HF calculation I get for the first H atom:
NoLondon
Diamagnetic contribution

A 189.736232 139.393758 0.000000
B 274.103959 201.376302 0.000000
C 0.000000 0.000000 197.314587
with the signs of the offdiagonal terms reversed for the second H atom.
With the same *.mol file (thus, the same ordering of H atoms)
London calculation gives
A 189.550915 146.733765 0.000000
B 259.481844 201.027507 0.000000
C 0.000000 0.000000 196.861315
and this leads to very reasonable
Total spin rotation constants

A 32.167417 19.594557 0.000000
B 43.706389 29.313292 0.000000
whereas in the NoLondon calculation the total is close to that reported
earlier (see below) for a DFT common origin job (and the error is removed
reversing the sign, with the change of 2*139.393758)
regards,
Michal
On Sun, 25 May 2014 14:30:14 +0200, noreply@daltonprogram.org wrote:
Posted by uachstno
When calculating spinrotation constants with common gauge origin the off
diagonal terms are incorrect.
Calculation with london orbitals:
34.084225 20.032869 0.000000
47.343131 30.898881 0.000000
0.000000 0.000000 32.643309
Calculation with common gauge in the center of mass:
34.255338 303.963380 0.000000
575.854478 30.607068 0.000000
0.000000 0.000000 32.207030
I have used uncontracted ccpvqz basis set to get converged results for
calculation with common gauge.
My guess is that the off diagonal contribution from electric field
integrals have wrong sing.
I have attached all imput files.
Stano

View the first unread post:
http://daltonprogram.org/forum/viewtopi ... ead#unread
Change your notifications settings:
http://daltonprogram.org/forum/ucp.php? ... boardwatch

 Posts: 570
 Joined: 15 Oct 2013, 05:37
 First name(s): Peter
 Middle name(s): Robert
 Last name(s): Taylor
 Affiliation: Tianjin University
 Country: China
Re: SpinRotation constants
I realize that the original poster may want to be doing isotopically substituted systems like HOD (say), given that symmetry was explicitly turned off and the Isotope keyword was given for each atom in the .mol file. Out of interest (and I have to say it is "out of interest" because I do not quite see how it could lead to a problem and know very little about these types of calculations), is the sign error still there if symmetry is turned on (or allowed to be discovered automatically)? And how do HOD calculatiosn compare between noLondon and London cases  is there still an obvious sign problem in the former?
Best regards
Pete
Best regards
Pete

 Posts: 7
 Joined: 15 Nov 2013, 11:46
 First name(s): Michal
 Last name(s): Jaszunski
 Affiliation: ICHO PAN
 Country: Poland
Re: SpinRotation constants
hello,
I repeated the previously described H2O calculation now allowing the
program to detect symmetry, and the results appear to be
all wrong.
Using another program I verified that correct results are obtained for
a) all the components without symmetry when London orbitals are used
b) diagonal components without symmetry in a .NOLONDON calculation
 as mentioned earlier, in this case there is most likely only a sign
errorin the calculation of the offdiagonal terms in the diamagnetic
contribution.
When symmetry is allowed, two H atoms are recognized as a pair, but
all the components of all the contributions (beginning with the nuclear
contribution to the spinrotation constant) are apparently wrong,
and that means all the components (including the diagonal ones and the
trace).
My guess is that at some stage in the calculation wrong coordinates
are used for the relevant nuclei
regards,
Michal
I repeated the previously described H2O calculation now allowing the
program to detect symmetry, and the results appear to be
all wrong.
Using another program I verified that correct results are obtained for
a) all the components without symmetry when London orbitals are used
b) diagonal components without symmetry in a .NOLONDON calculation
 as mentioned earlier, in this case there is most likely only a sign
errorin the calculation of the offdiagonal terms in the diamagnetic
contribution.
When symmetry is allowed, two H atoms are recognized as a pair, but
all the components of all the contributions (beginning with the nuclear
contribution to the spinrotation constant) are apparently wrong,
and that means all the components (including the diagonal ones and the
trace).
My guess is that at some stage in the calculation wrong coordinates
are used for the relevant nuclei
regards,
Michal

 Posts: 570
 Joined: 15 Oct 2013, 05:37
 First name(s): Peter
 Middle name(s): Robert
 Last name(s): Taylor
 Affiliation: Tianjin University
 Country: China
Re: SpinRotation constants
I guess I wish I hadn't asked what turning symmetry on would do!! Nevertheless, your (MJ's) observations and the earlier posting indicate that there's a problem (or maybe more than one) with calculating this tensor, and I guess one of the experts in the magnetic side of things (which I'm afraid does not include me) needs to look at this.
Best regards
Pete
Best regards
Pete
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