From owner-chemistry@ccl.net Wed Sep 23 00:40:00 2015 From: "Nico Green nicogreen6%x%gmail.com" To: CCL Subject: CCL: Constructive DFT suggestions appreciated Message-Id: <-51774-150922205745-3878-pkh4Q+TsxFUo46uGSni0Zw#%#server.ccl.net> X-Original-From: Nico Green Content-Type: multipart/alternative; boundary=001a11353a02ea3abb05205f9967 Date: Wed, 23 Sep 2015 00:57:30 +0000 MIME-Version: 1.0 Sent to CCL by: Nico Green [nicogreen6||gmail.com] --001a11353a02ea3abb05205f9967 Content-Type: text/plain; charset=UTF-8 While I think is the responsibility of each one of us to read, think and analyze when choosing the level of theory to use in any computational study we perform, the idea of what Alan meant was the idea of any discussion: If you are going to discredit something or someone, you should give a reason, not just because. That is my point of view of the subject, just don't say something isn't good (at a particular case) without justifying and if is possible give some thoughts of what should be a better choice. Nico On Tue, Sep 22, 2015 at 9:34 PM Susi Lehtola susi.lehtola!^! alumni.helsinki.fi wrote: > > Sent to CCL by: Susi Lehtola [susi.lehtola###alumni.helsinki.fi] > On 09/22/2015 02:31 PM, Alan Shusterman alan=-=reed.edu wrote: > > I have read several CCL messages over the past few weeks disparaging a > > correspondent's choice of DFT functional (usually B3LYP, but not always) > as > > being obsolete, useless, or both. > > > > These are perfectly fair opinions to share, but they are not > constructive. > > If you want to disparage a computational approach, fine with me, but > please > > recommend at least *one* better alternative. I would like to learn what > you > > think I should use, not just what I should not use. > > > > You don't need to cite publications or explain why you prefer a > particular > > functional. I can look that up once you tell me which functional(s) you > > think are worthy. > > This is certainly true. However, this *is* the computational chemistry > list, and most of the people here are scientists. The main duty of a > scientist is keep up to date with current methodology. Or, at least do a > literature search when someone tells you your method is outdated and > that you can get much better results with the same resources by using > more modern techniques, as has been pointed out (even with some > suggestions for alternatives) by many people on the forum. > > Unlike in the B3LYP/6-31G* days, where all you had was a hammer so every > problem started to look like nails, today there are specialized > methodologies for each field so general advice is harder to give, and so > the responsibility really rests on the researcher. > > [We wouldn't even be in the current jam if article reviewers were more > strict about the use of obsolete methodologies, but at that stage it is > somewhat too late. The reviewers might also not be computational chemists.] > -- > ----------------------------------------------------------------------- > Mr. Susi Lehtola, PhD Chemist Postdoctoral Fellow > susi.lehtola=alumni.helsinki.fi Lawrence Berkeley National Laboratory > http://www.helsinki.fi/~jzlehtol USA > -----------------------------------------------------------------------> > > --001a11353a02ea3abb05205f9967 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
While I think=C2=A0is the=C2=A0responsibility of each one = of us to read, think and analyze when choosing the level of theory to use i= n any computational study we perform, the idea of what Alan meant was the i= dea of any discussion:

If you are going to discredit som= ething or someone, you should give a reason, not just because.
That is my point of view of the subject, just don't say so= mething isn't good (at a particular case) without justifying and if is = possible give some thoughts of what should be a better choice.
Nico


=
On Tue, Sep 22, 2015 at 9:34 PM Susi Lehtola susi.lehtola!= ^!alumni.helsinki.fi <owner-chemistry:+:ccl.net> wrote:<= br>

Sent to CCL by: Susi Lehtola [susi.lehtola###alumni.helsinki.fi]
On 09/22/2015 02:31 PM, Alan Shusterman alan=3D-=3Dreed.edu wrote:
> I have read several CCL messages over the past few weeks disparaging a=
> correspondent's choice of DFT functional (usually B3LYP, but not a= lways) as
> being obsolete, useless, or both.
>
> These are perfectly fair opinions to share, but they are not construct= ive.
> If you want to disparage a computational approach, fine with me, but p= lease
> recommend at least *one* better alternative. I would like to learn wha= t you
> think I should use, not just what I should not use.
>
> You don't need to cite publications or explain why you prefer a pa= rticular
> functional. I can look that up once you tell me which functional(s) yo= u
> think are worthy.

This is certainly true. However, this *is* the computational chemistry
list, and most of the people here are scientists. The main duty of a
scientist is keep up to date with current methodology. Or, at least do a literature search when someone tells you your method is outdated and
that you can get much better results with the same resources by using
more modern techniques, as has been pointed out (even with some
suggestions for alternatives) by many people on the forum.

Unlike in the B3LYP/6-31G* days, where all you had was a hammer so every problem started to look like nails, today there are specialized
methodologies for each field so general advice is harder to give, and so the responsibility really rests on the researcher.

[We wouldn't even be in the current jam if article reviewers were more<= br> strict about the use of obsolete methodologies, but at that stage it is
somewhat too late. The reviewers might also not be computational chemists.]=
--
-----------------------------------------------------------------------
Mr. Susi Lehtola, PhD=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0Chemis= t Postdoctoral Fellow
susi.lehtola=3Dalumni.helsinki.fi=C2=A0 =C2=A0Lawrence Berkeley Nationa= l Laboratory
http://www.helsinki.fi/~jzlehtol=C2=A0 USA
-----------------------------------------------------------------------



-=3D This is automatically added to each message by the mailing script =3D-=
E-mail to subscribers: CHEMISTRY:+:ccl.net or use:
=C2=A0 =C2=A0 =C2=A0 http://www.ccl.net/cgi-bin/ccl/s= end_ccl_message

E-mail to administrators: CHEMISTRY-REQUEST:+:ccl.net or use
=C2=A0 =C2=A0 =C2=A0 http://www.ccl.net/cgi-bin/ccl/s= end_ccl_message

Subscribe/Unsubscribe:
=C2=A0 =C2=A0 =C2=A0 http://www.ccl.net/chemistry/sub_un= sub.shtml

Before posting, check wait time at: http://www.ccl.net

Job: http://www.ccl.net/jobs
Conferences: http://server.ccl.net/chemist= ry/announcements/conferences/

Search Messages: http://www.ccl.net/chemistry/sear= chccl/index.shtml
=C2=A0 =C2=A0 =C2=A0 http://www.ccl.net/spammers.txt

RTFI: http://www.ccl.net/chemistry/aboutccl/ins= tructions/


--001a11353a02ea3abb05205f9967--