The variable nrho when cos_th=True

[jjren]

Hi Prof. David Lauvergnat,
I have a question about the effect of variable nrho when I set cos_th = True in the name_transfo='poly' scheme.
It seems that nrho=1 or 2 will get the same result. Is this nrho neglected when cos_th = True?

&variables
nrho=1
Old_Qtransfo=f
nb_Qtransfo=3
Tana=t
/
&Coord_transfo name_transfo='bunch_poly' nb_vect=2 inTOout=f /
10. 1. 1.
O H H

&Coord_transfo name_transfo='poly' cos_th=t /
&vector nb_vect=1 Frame=t iAtA=1 iAtB=2 / : R1: A1->A2
&vector iAtA=1 iAtB=3 / : R2: A1->A3

&Coord_transfo name_transfo='active' /
1 1 1

&minimum Read_nameQ=t /
R1 2.
R2 1.1
c2 0.5
**
Best,
Jiajun

[lauvergn]

Dear Jiajun, In this case with cos_th=t, nrho=1 or nrho=2, you’ll get the same volume element and therefore the same KEO. - when cos_th=t, the coordinate is u=cos(theta) and the corresponding Euclidean volume element is dtau=du with nrho=1, you impose dtau=du with nrho=2, the volume element will be also dtau=du (Euclidean) - when cos_th=f, the coordinate is theta and the corresponding Euclidean volume element is dtau=sin(theta)dtheta with nrho=1, you impose dtau=dtheta (no sin(theta)) with nrho=2, the volume element will be also dtau=sin(theta)dtheta This explanation for nrho=2 is valable for Tnum, because the program don’t know which basis you’re going to used. The ElVibRot, the basis set is defined and it is very important to use a volume element adapted to the basis set. Therefore you must sets to nrho=2. Although, in some cases, nrho=1 will work as well and it will be equivalent to nrho=2. Can you tell me in which context, you are using ElVibRot/Tnum ? Best regards David

…

Le 5 nov. 2023 à 13:25, jjren ***@***.***> a écrit : Hi Prof. David Lauvergnat, I have a question about the effect of variable nrho when I set cos_th = True in the name_transfo='poly' scheme. It seems that nrho=1 or 2 will get the same result. Is this nrho neglected when cos_th = True? &variables nrho=1 Old_Qtransfo=f nb_Qtransfo=3 Tana=t / &Coord_transfo name_transfo='bunch_poly' nb_vect=2 inTOout=f / 10. 1. 1. O H H &Coord_transfo name_transfo='poly' cos_th=t / &vector nb_vect=1 Frame=t iAtA=1 iAtB=2 / : R1: A1->A2 &vector iAtA=1 iAtB=3 / : R2: A1->A3 &Coord_transfo name_transfo='active' / 1 1 1 &minimum Read_nameQ=t / R1 2. R2 1.1 c2 0.5 ** Best, Jiajun — Reply to this email directly, view it on GitHub <#26>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AEZ4ILSSFDJT5IHUNYEWGBDYC6AT3AVCNFSM6AAAAAA66JQYCGVHI2DSMVQWIX3LMV43ASLTON2WKOZRHE3TONZWGU3TCNI>. You are receiving this because you are subscribed to this thread.

------------------------------------------------------------------- David Lauvergnat tel +33 1 69 15 44 44 fax +33 1 69 15 44 47 Institut de Chimie Physique Bâtiment 349 15 avenue Jean Perrin UMR 8000 Universite Paris-Saclay 91405 Orsay Cedex http://pagesperso.lcp.u-psud.fr/lauvergnat/ email ***@***.*** ----------------------------------------------------------------

[jjren]

Dear David,

Thanks for your quick reply.
I'm using Tana to obtain the kinetic operator of molecules in polyspherical coordinates and then run quantum dynamics.
Your code is a great help to me.

Best,
Jiajun

[jjren]

Dear David,

Another question I have is whether it is possible to obtain kinetic operators that combine the angular coordinates (theta and phi) into j^2 , j^+ , j^−, and j_z, because my system is rather floppy and the singularity at theta=0 or pi can not be avoided. I decided to try 2D basis functions, such as spherical harmonics.

Best,
Jiajun

[lauvergn]

Dear Jiajun,

Another question I have is whether it is possible to obtain kinetic operators that combine the angular coordinates (theta and phi) into j^2 , j^+ , j^−, and j_z, because my system is rather floppy and the singularity at theta=0 or pi can not be avoided. I decided to try 2D basis functions, such as spherical harmonics.

With Tana, you cannot get an analytical KEO expression in terms of the j^2 , j^+ , j^−, and j_z. It should be possible to implement the feature, but it is a lot of work. Remark: With Tnum/ElVibRot, you can use spherical harmonic without repressing the operator in terms of j^2 , j^+ , j^−, and j_z. Another remark, since you want only the KEO, it is better to use TnumTana code (https://github.com/lauvergn/Tnum-Tana <https://github.com/lauvergn/Tnum-Tana>). The version ElVibRot-TnumTana is less maintained. Bes regards David

…

Best, Jiajun — Reply to this email directly, view it on GitHub <#26 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AEZ4ILW3U6SH72TTMPRYTTLYDTVC7AVCNFSM6AAAAAA66JQYCGVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMYTQMBTHE4DINJWGU>. You are receiving this because you commented.

------------------------------------------------------------------- David Lauvergnat tel +33 1 69 15 44 44 fax +33 1 69 15 44 47 Institut de Chimie Physique Bâtiment 349 15 avenue Jean Perrin UMR 8000 Universite Paris-Saclay 91405 Orsay Cedex http://pagesperso.lcp.u-psud.fr/lauvergnat/ email ***@***.*** ----------------------------------------------------------------

[jjren]

Dear David,

I see. Thank you very much!

Best,
Jiajun