From owner-chemistry -A_T- ccl.net Tue Jan 11 15:36:00 2022 From: "Marcos Verissimo Alves marcos_verissimo(0)id.uff.br" To: CCL Subject: CCL:G: Scientific notation in Gaussian 16 Message-Id: <-54579-220111150002-16931-3hD+M80JwIAeAqR5tbLDBA!A!server.ccl.net> X-Original-From: Marcos Verissimo Alves Content-Type: multipart/alternative; boundary="000000000000ad42e605d553e577" Date: Tue, 11 Jan 2022 16:59:20 -0300 MIME-Version: 1.0 Sent to CCL by: Marcos Verissimo Alves [marcos_verissimo(0)id.uff.br] --000000000000ad42e605d553e577 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Hi Andrew, In Fortran (I'm a Fortran programmer), we use "D" to designate a double-precision representation written in scientific notation, while "E" designates simple precision. That is very likely the reason for the "D" since a quick glance at the Wikipedia page for the list of Quantum Chemistry and Solid-State Physics software shows that Gaussian is written in Fortran. Best regards, Marcos --- Dr. Marcos Verissimo Alves Prof. Adjunto II, Curso de F=C3=ADsica Computacional Instituto de Ci=C3=AAncias Exatas Universidade Federal Fluminense Volta Redonda - RJ, Brasil Em ter., 11 de jan. de 2022 =C3=A0s 16:33, Andrew DeYoung andrewdaviddeyoun= g### gmail.com escreveu: > Hi, > > It appears that various quantities that are output by Gaussian 16 use > notation of the form 6.626D-34. Is it correct for me to assume that this > represents 6.626*10^(-34), and is equivalent to the scientific notation > 6.626E-34 or 6.626e-34 used in other areas, such as in C/C++, Python, and > MATLAB? Or does the "D" represent anything different from, or in additio= n > to, "*10^"? > > Thank you for bearing with me with this question. (I am what we call in > the US a millennial, and am not terribly well acquainted with the sometim= es > historical origins and meanings of notation!) > > Best, > Andrew > > Andrew DeYoung, PhD > Department of Chemistry > Carnegie Mellon University > --000000000000ad42e605d553e577 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Hi Andrew,

In Fortran (I'm a Fortra= n programmer), we use "D" to designate a double-precision represe= ntation written in scientific notation, while "E" designates simp= le precision. That is very likely the reason for the "D" since a = quick glance at the Wikipedia page for the list o= f Quantum Chemistry and Solid-State Physics software=C2=A0shows that Ga= ussian is written in Fortran.

Best regards,
<= div>
Marcos
---
Dr. Marcos Verissimo Alves
Prof. Adjunto II, Cur= so de F=C3=ADsica Computacional
= Instituto de Ci=C3=AAncias Exatas
Universidade Federal= Fluminense
Volta Redonda - RJ, Brasil

<= /div>


Em ter., 11 de jan. de 2022 =C3=A0s = 16:33, Andrew DeYoung andrewdaviddeyoung###gma= il.com <owner-chemistry(-)c= cl.net> escreveu:
Hi,

It appears that various = quantities that are output by Gaussian 16 use notation of the form 6.626D-3= 4.=C2=A0 Is it correct for me to assume that this represents 6.626*10^(-34)= , and is equivalent=C2=A0to the scientific notation 6.626E-34 or 6.626e-34 = used in other areas, such as in C/C++, Python, and MATLAB?=C2=A0 Or does th= e "D" represent anything different from, or in addition to, "= ;*10^"?

Thank you for bearing with me with th= is question.=C2=A0 (I am what we call in the US a millennial, and am not te= rribly well acquainted with the sometimes historical origins and meanings o= f notation!)

Best,
Andrew

=
Andrew DeYoung, PhD
Department of Chemistry
= Carnegie Mellon University
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