IPCCSD

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hello,

I am trying to run the QA for f2 IP-EOMCCSD calculation:

start  tce_ipccsd_f2
title "tce_ipccsd_f2"
echo

memory stack 1000 mb heap 200 mb global 500 mb

geometry units angstroms
symmetry c1
 F    0.0000000000        0.0000000000   0.7059650
 F    0.0000000000        0.0000000000  -0.7059650
end

basis spherical
 * library cc-pvdz
end

scf
 thresh 1.0e-10
 tol2e 1.0e-10
 singlet
 rhf
end

tce
 ipccsd
 nroots 1
 freeze atomic
 thresh 1.0e-7
end

task tce energy


and I get the following:

------------------------------------------------------------------------
 tce_input: unknown directive                   0
 ------------------------------------------------------------------------
 ------------------------------------------------------------------------
  current input line : 
    25:  ipccsd
 ------------------------------------------------------------------------
 ------------------------------------------------------------------------


I did set: EACCSD=y, IPCCSD=y before compiling.

anyone have any thoughts?

Forum Regular
Threads 59
Posts 283
There is no problem to finish the calculation using the original input
...

 Iterations converged
------------------

Excited state root  1
Excitation energy / hartree = 0.554880518711330
/ eV = 15.099073582827467
...

The accompanying QA test gives


...
Excited state root 1
Excitation energy / hartree =        0.554880518711318
/ eV = 15.099073582827138
Edited On 7:54:10 PM PST - Thu, Feb 21st 2019 by Xiongyan21

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Threads 59
Posts 283
I have just installed the updates of the oprating system, and have not recompile NWCHEM6.8, and now the calculation gave different excitation orbitals.

I have put the log files on github, and you can refer to them.

I will recompile it and see.

They are also different on macOS High Sierra.

I have put the log files on github.

Recompilation of NWCHEM6.8 on Ubuntu makes the double contribution different.
Edited On 5:09:28 PM PDT - Sun, Jun 24th 2018 by Xiongyan21

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Posts 15
Hi,

the job doesn't run at all (ubuntu 16.04, nwchem 6.8), it doesn't recognize the 'IPCCSD' keyword.

Afik

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Posts 283
I think you do not compile it correctly.
On Ubuntu 17.10 with NWCHEM6.8, I have repeated the calculation for 6 times before recompilation, and two times after recompilation; and 4 times on MAC, of which 12 log files have all been put on github.
Edited On 3:33:57 PM PDT - Sun, Mar 10th 2019 by Xiongyan21

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the problem seems to have been fixed by restarting the machine, weird

Forum Regular
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I have asked precompiled GAMESS for MAC to do the same calculation here with IP-EOM3A, i.e., up to 3h2p excitations. I used mp2 to optimize the geometry and changed the basis set into aug-cc-pVTZ to obtain IE, and it could be 15.749 eV. It is wonderful for GAMESS to begin with an RHF calculation and then automatically enter an ROHF one.
GAMESS IP-EOM2 including up to 2h1p excitations could give the IE of 15.619 eV, and NIST Chemistry Webbook gives vertical IE of 15.70 eV.

With the original input, the first excitation energy from NWCHEM is 15.099073582827474eV, around 0.6 eV deviating from experimental data. Perhaps this is not IE, but IE would be obtained based on this calculation.

GAMESS ROHF IP-EOM2 could give IE of F atom 17.35944 eV using aug-cc-pV5Z, and that of 17.42282 eV on NIST Chemistry Webbook.

ROHF treatment of radicals and other open-shell systems is one of the great challenges in computational quantum chemistry, and it is very likely that the IP calculated employing IP-eom2 has a large discrepancy, or is completely wrong when compared with experimental data, especially for a system with significant multireference features.

The successful calculation of such a situation in GAMESS lies in its employment of the artful and ingenious IP-EOM3A and EA-EOM3A to provide results. I did this way and obtained IE of CH3 whose geometry mp2 optimized of 9.67 eV when the number of active orbital was one and the basis set was aug-cc-pVQZ, compared with experimental 9.84+-0.01 eV on NIST Chemist Webbook.

I think we should make things physical and rational although the deviance might be larger when compared experimental data.

The open-shell EA and IP coupled-cluster programs in GAMESS were pogrammed by Dr. Gour, Prof. Piecuch, and Prof. Wloch, evaluated and assembled by Prof. Gordon, Dr. Schmidt and other doctors in Prof. Gordon's Group or Ames Laboratory.
Edited On 5:30:32 PM PDT - Sun, Mar 10th 2019 by Xiongyan21

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Can the motivation of the different excitation orbitals be enlightened by the article of Prof. Gordon, et al.: Can Orbitals Really Be Observed in Scanning Tunneling Microscopy Experiments?
Edited On 6:07:20 AM PST - Sat, Feb 2nd 2019 by Xiongyan21

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I can verify the first excitation energy obtained is the first IP using NWCHEM because when I changed the keyword IPCCSD into CCSD in TCE, the obtained first excitation energy is much lower, i.e., 4.691836421578004eV, which is also significant larger than that using the multireference CI method in an article and those calculated by TDDFT or experimental data indexed in another one, thus the IP obtained by NWCHEM are unsuccessful for F2, and the first excitation energy is almost also.
Edited On 5:38:03 AM PST - Wed, Jan 30th 2019 by Xiongyan21


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