[molpro-user] geometry Optimization

[Antara Dutta]

Hello User, I'm wondering if anyone could please help me on the following problem. I'm trying to do CASSCF calc. on 1,3,5-trimethylene benzene triradical using Molpro2002.6. The active space is (9,9) and geometry D3h which molpro is caluculating in C2v as non abelian group. I'm trying to optimize geometry for ground state (4A1" in D3h) but it crashes due to symmetry breaking. I suppose my active space is not chosen correctly to prevent the symmetry breaking. Also I would like to optimize low lying 2B1 and 2A2 states in C2v  to look  for Jahn-Teller distorsion.Any suggession on  how should I change my input to get optimized geometry is appreciated. Please find below the input. Best regards, Antara memory,20,m; basis=6-31G** zmat,ang; C X  1  1.0 C  1  r1   2  a1 H  1  r2   2  a1   3  a2 C  1  r3   2  a1   3  a3 C  1  r4   3  a4   2  a2 C  1  r4   3  a4   2  a3 C  3  r4   1  a4   2  a2 C  3  r4   1  a4   2  a3 C  8  r3   3  a5   6  a3 C  9  r3   3  a5   7  a3 H  5  r5   1  a5   2  a2 H  5  r5   1  a5   2  a3 H  6  r5   1  a5   5  a2 H  7  r5   1  a5   5  a2 H 10  r5   8  a5   6  a2 H 11  r5   9  a5   7  a2 H 10  r5   8  a5   3  a2 H 11  r5   9  a5   3  a2 end r1=2.850 r2=3.940 r3=1.405 r4=1.424 r5=1.085 a1=90.0 a2=0.0 a3=180.0 a4=60.0 a5=120.0 rhf; wf,63,4,3; label1; multi; occ,16,6,11,3; close,16,0,11,0; wf,63,4,3;state,1; natorb,ci,print; if(status.le.0) then goto,label1,[-1],[3] endif optg;   ****************************************************************** Antara Dutta Emerson Center for Scientific Computation & Deptt. of Chemistry, Emory University, Atlanta, GA 30322, USA.