How to do optimization in Td

[Boggavarapu, Kiran]

> Hi All:
> 
> I have a problem in optimizing Td molecules with Molpro. Since Molpro can do only abelian groups, I started optimizing in D2 point group. The coordinate system is simple, taking CH4 as example, C at the origin the remaining four H atoms have  same numerical x, y and z coordinates but x-is-not-equal-to-y-is-not-equal-to-z.
> However, Molpro recognizes it as D2 and start doing optimization, it begins with 
> Computing numerical gradient for displacement coordinate   1
>  beginning of seg1mn b(1) =    0.00000000000000D+000
>  beginning of seg1mn b(1) =    0.00000000000000D+000
> 
> and do only on cycle and exist.
> 
> WHY! does anyone know the answer.
> 
> 
> Thanks in advance
> 
> regards
> Kiran
> 
> Kiran Boggavarapu
> PNNL, PO Box 999,
> MS K8-91
> Richland, WA 99352
> Phone:  509-376-2723 (office)
>             509-374-4023 (home)
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> "Science is facts; just as houses are made of stones, so is science made of facts; but a pile of stones is not a house and a collection of facts is not necessarily science." 
> Henri Poincare
> 
>