[molpro-user] LCCSD(T) is more time and memory consuming than CCSD(T)

[Leonid Shirkov]

Dear Molpro Community,

I was testing the basis set convergence of LCCSD(T)
for some small molecules and found out that it is more time
consuming that conventional CCSD(T) for the same orbital basis set.

My tests for water showed that CCSD(T)/av5z requires 50,m and
runs much faster than LCCSD(T)/av5z which requires at least 400,m and gives
 "insufficient memory available" error otherwise (two inputs are attached).

I understand that there are many options for LCCSD(T) which have
effect on its performance, but shouldn't be LCCSD(T), especially the
DF version, be faster and less demanding than conventional CCSD(T)?


Best regards,
Leonid
-------------- next part --------------
A non-text attachment was scrubbed...
Name: e_h2o_df-ccsd-t_av5z_1.inp
Type: application/octet-stream
Size: 255 bytes
Desc: not available
URL: <http://www.molpro.net/pipermail/molpro-user/attachments/20180218/8e7c18c9/attachment.obj>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: e_h2o_df-ccsd-t_av5z_2.inp
Type: application/octet-stream
Size: 255 bytes
Desc: not available
URL: <http://www.molpro.net/pipermail/molpro-user/attachments/20180218/8e7c18c9/attachment-0001.obj>