# [molpro-user] Phase changes in EOM-CCSD transition moments

John Montgomery johnm at phys.uconn.edu
Sat Sep 27 18:26:54 BST 2014

```I am trying to compute potential curves and transition moments
for NaCa+ using the following input:

!
***,naca+

memory,250,M
gthresh, zero=1.d-14, oneint=1.d-14, twoint=1.d-14, energy=1.d-12

basis=tzvpp

d=[5,6,7,8,9,10,11,12]

do i=1,#d
! NaCa+
geometry={Na; Ca 1 d(i)}
set,charge=1

rhf
ccsd
eom,-6.1,trans=1

es1(i)=energy(1)
es2(i)=energy(2)
es3(i)=energy(3)
es4(i)=energy(4)
es5(i)=energy(5)
es6(i)=energy(6)

t1(i)=trdmz(1)
t2(i)=trdmz(2)
t3(i)=trdmz(3)
t4(i)=trdmz(4)
t5(i)=trdmz(5)
enddo

ezero=es1(#d)
do i=1,#d
d1(i)=(es1(i)-ezero)*tocm
d2(i)=(es2(i)-ezero)*tocm
d3(i)=(es3(i)-ezero)*tocm
d4(i)=(es4(i)-ezero)*tocm
d5(i)=(es5(i)-ezero)*tocm
d6(i)=(es6(i)-ezero)*tocm
enddo

table,d,t1,t2,t3,t4,t5
digits,2,6,6,6,6,6

table,d,d1,d2,d3,d4,d5,d6
digits,2,2,2,2,2,2,2

table,d,es1,es2,es3,es4,es5,es6
digits,2,6,6,6,6,6,6

Here is a fragment of the output showing the calculated values for
the transition moments:

D       T1          T2          T3          T4          T5
5.00    2.680056    0.000000    0.486337    0.529354 0.000000
6.00   -2.821376    0.000000   -0.258984    0.410843 0.363768
7.00    2.958102   -0.333122    0.000000   -0.182220 0.427673
8.00   -2.982678    0.966502    0.000000    0.272120 -0.456876
9.00    2.934224   -1.394942    0.000000   -0.791324 0.258189
10.00    2.957459   -1.564050    0.000000    0.953963 0.475171
11.00   -2.890902    1.875505    0.000000   -0.643294 -0.693953
12.00   -2.615037   -2.091379    0.632267    0.000000 -0.765586

Looking at the results for ground to first excited state, it appears that
there are phase changes along the curve.  My inclination is to just flip
the signs, but I'd like to be more systematic.  Is there any way to track
the phase of the calculated states?  I would be grateful for any

--
John A. Montgomery, Jr., Ph.D
Research Professor
Department of Physics, U-3046
University of Connecticut