[molpro-user] question about energy after uks optg

[Ling Tong]

Dear All,

I have a question about the energy after uks optg. I calculated some metal
hydride,such as MH2(M=Sc-Zn), and CrHn(n-2,4,6) using uks/b3lyp and basis set SDD
for M, 6-311++G(d,p) for H. I used occ;closed;wf; to set the orbitals. But the
energy after opt is higher than the first input. It always go high after one or
two optimization, and then go down slowly and stop. Sometimes when I only use wf,
energy after opt is lower than input, but most is still higher. I don't know why?

The following is my input:

***,TiH2
geometry={Ti;
          H1,Ti,R;
          H2,Ti,R,H1,Theta}
R=1.749 ang
theta=122
basis={
ecp,ti,ECP10MDF;
spd,ti,ECP10MDF;c;
spd,h,6-311++G(d,p);c;
}
df=b3lyp
uks
occ,4,1,2,1
closed,3,1,2,0
wf,14,4,2
optg
show,R,theta
frequencies

Thank you for kind help!!
Best wishes,
Sincerely,
yuna