[molpro-user] quinone partial optimization

[Kirk Peterson]

Dear George,

it looks to me that your z-matrix variables are not sufficiently constrained to keep C2 symmetry, i.e., after the calculation of the gradient, the first downhill step wants to take it away from C2 symmetry, which causes the crash.  Shouldn't some of your bond distances and angles be equivalent by symmetry?  If so, each of these should be represented by just one variable.  Perhaps there is more going on than this, but certainly this is partly to blame.

-Kirk


On Mar 7, 2011, at 10:36 AM, george wrote:

> Dear molpro users
>                                i tried to do partial optimization for the molecule C8H6F2 which is a subtituted quinone with ch2 and cf2 group at para position
> i wrote zmat for this molecule and made only one of the variable (dihedral angle) inactive in the optg command the molecule belongs to c2 symmetry
> when i run the input it does single point energy calculation initially and when it comes to optimization stage it displays the following error message and exit
>  The request for symmetry elements XY, cannot be honoured
>  ? Error
>  ? Symmetry problem
>  ? The problem occurs in zmatrix.f:zmat_orient
> when i give nosym card at the begining of input file the program runs without any problem but i want to do partial optimization in C2 symmetry only
> i put the input file below
> 
> ***,quinone in C2 geometry partial optimization
> print,basis,orbitals,civector
> angstrom
> geometry={
> X
> X  1  1.0
> C  2  XC3  1   90
> C  2  XC4  1   90   3   B1
> C  2  XC5  1   90   4   B2
> C  2  XC6  1   90   5   B3
> C  2  XC7  1   90   6   B4
> C  2  XC8  1   90   7   B5
> X  3  1.0  2   90   1   0
> C  3  C1   9   90   2   180
> H  4  HC4  3   A32  2   180
> H  5  HC5  4   A42  2   180
> C  6  C2   5   A52  2   180
> H  7  HC7  6   A62  2   180
> H  8  HC8  7   A72  2   180
> H 10  H1   3   B6   4   D1
> H 10  H1   3  -B6   4   D1
> F 13  F1   6   B6   5   D1
> F 13  F1   6  -B6   5   D1
> }
> 
> A32 = 120.0
> A42 = 120.0
> A52 = 120.0
> A62 = 120.0
> A72 = 120.0
> XC3 = 1.3
> XC6 = 1.3
> XC4 = 1.3
> XC5 = 1.3
> XC7 = 1.3
> XC8 = 1.3
> HC4 = 1.08
> HC8 = 1.08
> HC5 = 1.08
> HC7 = 1.08
> C1  = 1.40
> C2  = 1.40
> B1  = 60.0
> B2  = 60.0
> B3  = 60.0
> B4  = 60.0
> B5  = 60.0
> H1  = 1.08
> H2  = 1.08
> F1  = 1.30
> F2  = 1.30
> B6  = 120.0
> B7  = 120.0
> D1  = 10
> 
> basis = vdz
> hf
> {optg;inactive,D1}
> put,molden,ben_c2v.molden
> ---
> 
> can any one help me to run partial optimization in C2 symmetry 
> 
> -- 
> 
> 
> 
> F George Densingh Xavier
> Post doctoral Research Associate of Prof. Shmuel Zillberg
> Institute of Chemistry (Los Angeles Building)
> The Hebrew University of Jerusalem
> Edmond J. Safra Campus
> Givat Ram, Jerusalem 91904
> ISRAEL
> 
> Mobile 054-3913952
> 
> george.xavier at mail.huji.ac.il
> 
> 
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