Keyword EXCHANGE is uninitialized in rem vector

Questions
#1

Hi, I want to get the ground state absorption spectrum. But I got a error mesagge ¨Keyword EXCHANGE is uninitialized in rem vector¨. Has anyone come across this erorr and how to solve it? Here is the input file:
$rem
!QSYS wt=6h
jobtype sp
method CAM-B3LYP
basis def2-TZVP
mem_total 100000
threads 16
cis_n_roots 50
cis_singlets true
cis_triplets false
SOLVENT_METHOD = PCM
$end

$solvent
Dielectric 1.9
$end

$molecule
0 1
C -2.9894616522 3.6766388145 -0.1354791520
C -3.7342001838 2.8440408482 -0.9685344512
C -2.1703177715 3.1082913419 0.8380089954
C -3.6558713820 1.4611268139 -0.8395697058
C -2.1004875743 1.7267873281 0.9849002974
C -2.8399116808 0.8862524770 0.1430568422
N -2.7622309898 -0.5202455487 0.2837410923
C -3.9348624998 -1.3076124922 0.1943606306
C -1.5077260855 -1.1396063325 0.5013256506
C -5.1256600423 -0.8839312627 0.7983662529
C -6.2784110116 -1.6564119218 0.7002741933
C -6.2628303633 -2.8701918477 0.0160753077
C -5.0778791623 -3.2995214932 -0.5782814570
C -3.9254760325 -2.5243415548 -0.4996179702
C -0.3746114019 -0.7212801338 -0.2080626452
C 0.8578942377 -1.3270164932 0.0136692233
C 0.9803616469 -2.3693622352 0.9302632416
C -1.3784850088 -2.1810409762 1.4289526099
C -0.1462758591 -2.7938794042 1.6319201291
H -3.0474021614 4.7615589729 -0.2440159043
H -4.3768664452 3.2744444621 -1.7400700962
H -1.5852558495 3.7480815125 1.5028585131
H -4.2314408863 0.8145390149 -1.5038212006
H -1.4672506884 1.2881583676 1.7575815053
H -5.1432298236 0.0592484443 1.3466188671
H -7.1977692152 -1.3085196967 1.1770461360
H -7.1676779215 -3.4772614374 -0.0531858998
H -5.0499759530 -4.2459982110 -1.1231680326
H -3.0048756068 -2.8610547249 -0.9786362805
H -0.4664082386 0.0860720266 -0.9363238010
H 1.7307214151 -0.9868633383 -0.5484126749
H 1.9475665888 -2.8478911505 1.0966686657
H -2.2536770070 -2.5096568557 1.9915507096
H -0.0651416905 -3.6057127140 2.3585011081
$end

#2

What version of Q-Chem are you running? This seems like a relic of old versions where functionals were specified with keywords EXCHANGE and CORRELATION but for certain that could not be separated in that way (e.g., B3LYP), only the EXCHANGE keyword was used. Recent versions of Q-Chem replace this with METHOD for nearly all functionals, including CAM-B3LYP (I just checked, and your input runs fine with Q-Chem 6.0 but probably earlier versions also). As a workaround, it may be possible to specify CAM-B3LYP using a $xc_functional input section and EXCHANGE = GEN. See the keywords HF_SR and HF_LR in the manual, which stipulate the fractions of short- and long-range Hartree-Fock exchange.

#3

Thanks for your reply! The version of Q-Chem I am using is qchem-5.3. But how to specify the CAM-B3LYP by means of an $xc_functional input section?
¨The CAM-B3LYP functional comprises of 0.19 Hartree–Fock (HF) plus 0.81 Becke 1988 (B88) exchange interaction at short-range, and 0.65 HF plus 0.35 B88 at long-range. The intermediate region is smoothly described through the standard error function with parameter 0.33.¨(Chem. Phys. Lett. (2004), 393, pp. 51.). How to get corresponding Hartree-Fock exchange, exchange_symbol and correlation_symbol from 5.3.7 User-Defined Density Functionals‣ 5.3 Overview of Available Functionals ‣ Chapter 5 Density Functional Theory ‣ Q-Chem 6.0 User’s Manual?

#4

Can you figure it out from the example that’s in the sample job dft/srsh_pcm.in ? If not I will take a look when I find some time.

#5

Sorry, I tried but failed. I would like to appreciate if you could help me.

#6

Have you tried simply EXCHANGE = CAM-B3LYP? That’s what I was trying to say about the older version of functional specification. In current version of Q-Chem, that gives same result as METHOD = CAM-B3LYP.

#7

Yes, I just tried that and the result is the same–¨ Keyword EXCHANGE is uninitialized in rem vector¨.

#8

Please post that full input file.

#9

$rem
!QSYS wt=6h
jobtype sp
exchange CAM-B3LYP
basis def2-TZVP
mem_total 100000
threads 16
cis_n_roots 50
cis_singlets true
cis_triplets false
SOLVENT_METHOD = PCM
$end

$solvent
Dielectric 1.9
$end

$molecule
0 1
C -2.9894616522 3.6766388145 -0.1354791520
C -3.7342001838 2.8440408482 -0.9685344512
C -2.1703177715 3.1082913419 0.8380089954
C -3.6558713820 1.4611268139 -0.8395697058
C -2.1004875743 1.7267873281 0.9849002974
C -2.8399116808 0.8862524770 0.1430568422
N -2.7622309898 -0.5202455487 0.2837410923
C -3.9348624998 -1.3076124922 0.1943606306
C -1.5077260855 -1.1396063325 0.5013256506
C -5.1256600423 -0.8839312627 0.7983662529
C -6.2784110116 -1.6564119218 0.7002741933
C -6.2628303633 -2.8701918477 0.0160753077
C -5.0778791623 -3.2995214932 -0.5782814570
C -3.9254760325 -2.5243415548 -0.4996179702
C -0.3746114019 -0.7212801338 -0.2080626452
C 0.8578942377 -1.3270164932 0.0136692233
C 0.9803616469 -2.3693622352 0.9302632416
C -1.3784850088 -2.1810409762 1.4289526099
C -0.1462758591 -2.7938794042 1.6319201291
H -3.0474021614 4.7615589729 -0.2440159043
H -4.3768664452 3.2744444621 -1.7400700962
H -1.5852558495 3.7480815125 1.5028585131
H -4.2314408863 0.8145390149 -1.5038212006
H -1.4672506884 1.2881583676 1.7575815053
H -5.1432298236 0.0592484443 1.3466188671
H -7.1977692152 -1.3085196967 1.1770461360
H -7.1676779215 -3.4772614374 -0.0531858998
H -5.0499759530 -4.2459982110 -1.1231680326
H -3.0048756068 -2.8610547249 -0.9786362805
H -0.4664082386 0.0860720266 -0.9363238010
H 1.7307214151 -0.9868633383 -0.5484126749
H 1.9475665888 -2.8478911505 1.0966686657
H -2.2536770070 -2.5096568557 1.9915507096
H -0.0651416905 -3.6057127140 2.3585011081
$end

Thank you!

#10

In Q-Chem 6.0, this input runs and produces same result as METHOD=CAM-B3LYP. Therefore I suggest that you contact Q-Chem technical support to see if they can reproduce this behavior with an older version of Q-Chem.

#11

OK, Thank you immensely!