From owner-chemistry@ccl.net Thu May 26 00:52:00 2022 From: "Jan Labanowski jasienku]=[gmail.com" To: CCL Subject: CCL: CCL should work now, I believe Message-Id: <-54713-220526004929-22382-CDzWHhdz5lsYqVnTtil61Q_-_server.ccl.net> X-Original-From: Jan Labanowski Content-Type: multipart/alternative; boundary="000000000000ecc3f505dfe2e90a" Date: Thu, 26 May 2022 00:49:13 -0400 MIME-Version: 1.0 Sent to CCL by: Jan Labanowski [jasienku*gmail.com] --000000000000ecc3f505dfe2e90a Content-Type: text/plain; charset="UTF-8" Dear CCL, Dear CCL Members, I moved the CCL to a new IP address space, and it should work like before. The email will be now coming from the 99.50.89.186 so please whitelist this address. It now only have the SPF DNS record to confirm that messages are legit and will work on DKIM later. Of course, I may have missed something, so please report to chemistry-request~~ccl.net if you find some new or old glitches. I know about many, but since I will be redoing the CCL on the cloud, some will have to wait. I had a problem with my provider with an email. They block the outgoing port 25 on their firewalls, and I had to convince them that I am not a spammer and I send tons of mail for noble causes, and that I am a "doctor without borders". With the time that this migration gave me, I will start thinking of the future rendition of CCL, then prototype something, test it, and we will move to a new venue in the clouds. Please send me some more suggestions and wishes. I will do what I can, but it will be a compromise. There are some legal issues with running the CCL. I have to be a "phone company" and I cannot be responsible for the content of messages. There are issues of export controls and "loss of profits" if companies think that CCL unjustly defamed them. Believe it or not, I was sent the "cease-and-desist" letters in the past. And I cannot "approve" messages. If you sent a message and it did not appear during the transition, please resend it, which will be the easiest way out of this mess. Thank you for your patience. Jan -- Jan Labanowski CCL Maintainer ccl~~ccl.net , jasienku~~gmail.com --000000000000ecc3f505dfe2e90a Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Dear CCL,

Dear CCL Members,

I moved the= CCL to a new IP address space, and it should work like before.
The emai= l will be now coming from the 99.50.89.186 so please whitelist this
addr= ess. It now only have the SPF DNS record to confirm that messages are
le= git and will work on DKIM later.

Of course, I may have missed someth= ing, so please report to
ch= emistry-request~~ccl.net
if you find some new or old glitches. I know= about many, but since
I will be redoing the CCL on the cloud, some will= have to wait.

I had a problem with my provider with an email. They = block the outgoing port
25 on their firewalls, and I had to convince the= m that I am not a spammer
and I send tons of mail for noble causes, and = that I am a "doctor without
borders".

With the time tha= t this migration gave me, I will start thinking of the
future rendition = of CCL, then prototype something, test it, and we will
move to a new ven= ue in the clouds. Please send me some more suggestions
and wishes= . I will do what I can, but it will be a compromise. There are some
lega= l issues with running the CCL. I have to be a "phone company" and=
I cannot be responsible for the content of messages. There are issuesof export controls and "loss of profits" if companies think tha= t CCL
unjustly defamed them.=C2=A0 Believe it or not, I was sent the &qu= ot;cease-and-desist"
letters in the past. And I cannot "approv= e" messages.

If you sent a message and it did not appear during= the transition,
please resend it, which will be the easiest way out of = this mess.

Thank you for your patience.

Jan
--
Jan Laba= nowski
CCL Maintainer
ccl~~ccl.net = , jasienku~~gmail.com
--000000000000ecc3f505dfe2e90a-- From owner-chemistry@ccl.net Thu May 26 17:03:01 2022 From: "Hugo Alejandro Jimenez Vazquez hjimenez.:.woodward.encb.ipn.mx" To: CCL Subject: CCL:G: Maximum number of cycles in Gaussian Message-Id: <-54714-220526021947-32600-WhtD1r/gnQQWGWwiuK4jKA(0)server.ccl.net> X-Original-From: Hugo Alejandro Jimenez Vazquez Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Date: Thu, 26 May 2022 01:34:11 -0500 (CDT) MIME-Version: 1.0 Sent to CCL by: Hugo Alejandro Jimenez Vazquez [hjimenez[*]woodward.encb.ipn.mx] Hi, In addition to Cory's comments there are a couple of things to think about when you run out of optimization cycles. For a "typical" molecule of 30 or so atoms, the number of optimization cycles that Gaussian assigns, should be more than enough to reach a minimum. If it doesn't then you should consider one of several possible scenarios: 1. Your starting geometry is way off the minimum. If this is indeed the case, you could take the final geometry of the failed optimization and submit it to a new optimization. 2. Your optimization is oscillating. In this case it is likely that the optimization will not reach a minimum. Why the optimizer oscillates in some cases but not in others I don't know. You can detect it by using something like Molden, which allows you to follow the optimization step by step. It also allows you to plot energy vs. step. (If you don't have Molden you can "grep" the energy of each optimization step in the output file and analyze the corresponding values.) If the optimization is oscillating you will see that the energy goes up and down in the plot, never falling to a minimum. If this happens, there are a number of things you can try to get to the minimum: - Calculate the force constans at the beginning of the optimization. - Carry out the optimization in internal coordinates. - Carry out the optimization in cartesian coordinates. - Use a different optimization algorithm. - Some DFT methods (M06-2X combined with diffuse functions, for example) also tend to cause the optimizer to oscillate and then you have to use additional options such as INT(GRID=ULTRAFINE,ACC2E=11) and SCF(TIGHT,NOVARACC,NOINCFOCK). Or just choose another functional. I did... Regards, --- Hugo A. Jimenez Vazquez hjimenez#%#woodward.encb.ipn.mx Departamento de Quimica Organica ENCB-IPN Mexico On Mon, 23 May 2022, Andrew DeYoung andrewdaviddeyoung . gmail.com wrote: > Hi, > > I'm running Gaussian 16. Could someone please help me understand how > "number of steps" and MaxCycles work in Gaussian? I have a molecule whose > geometry I want to optimize to a local minimum, at the B3LYP/6-31G(d,p) > level. I tried this method section in my input: > > # Opt(MaxCycles=300) B3LYP/6-31G(d,p) > > In the documentation for the Opt keyword ( > https://gaussian.com/opt/?tabid=1#Opt_keyword__MaxCycles_option ), it says > that "MaxCycles=N sets the maximum number of optimization steps to N. The > default is the maximum of 20 and twice the number of redundant internal > coordinates in use (for the default procedure) or twice the number of > variables to be optimized (for other procedures)." > > I'm not sure what it means by "redundant internal coordinates." I did not > explicitly specify redundant coordinates (as I think one might do for a > Scan calculation). My Z-matrix has 31 lines (31 atoms). On the other > hand, my variables section contains 87 lines: 30 bonds (B1-B30), 29 bond > angles (A1-A29), and 28 dihedral angles (D1-D28). > > When I run my optimization, Gaussian terminates after a few hours with a > Link 9999 error; the end of the log file reads, "Error termination request > processed by link 9999." I think this usually means the optimization has > failed to converge, and if I scroll up a bit in the log file, I see that is > the case. In the final "GradGrad..." section, it reads: > > Optimization stopped. > -- Number of steps exceeded, NStep= 186 > -- Flag reset to prevent archiving. > > Why specifically did optimization stop after 186 steps -- what am I missing > here? Are "number of steps" and MaxCycles the same? If so, why didn't > optimization continue until NStep=300 was reached or until the calculation > converged? If not, how are they different? > > I was able to reach convergence by running a new optimization -- with the > last geometry of the previous run as the starting configuration -- but in > the future, how can I increase the maximum number of allowed steps? > > (By the way, if I remember correctly, the default number of cycles is 128 > if MaxCycles is not specified. Also, I believe the notation used in older > versions of Gaussian was, for example, 'OptCyc=300' but I believe it's now > 'Opt(MaxCyc=300)' for Gaussian 16. See, for example, > https://gaussian.com/obsolete/ I think that 'MaxCyc' is just an allowed > abbreviation of 'MaxCycles'.) > > Thank you very much for your time! > > Best, > Andrew > > Andrew DeYoung, PhD > Department of Chemistry > Carnegie Mellon University >