From owner-chemistry -A_T- ccl.net Tue Jan 11 16:11:00 2022 From: "Johannes Margraf margraf]=[fhi-berlin.mpg.de" To: CCL Subject: CCL:G: Scientific notation in Gaussian 16 Message-Id: <-54580-220111151216-27766-HhwaYd9ZzIZ7kyP2+1oKZg,,server.ccl.net> X-Original-From: Johannes Margraf Content-Type: multipart/alternative; boundary="=_75e476819f659470b0ecc452b4c18101" Date: Tue, 11 Jan 2022 21:12:08 +0100 MIME-Version: 1.0 Sent to CCL by: Johannes Margraf [margraf|,|fhi-berlin.mpg.de] --=_75e476819f659470b0ecc452b4c18101 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=US-ASCII; format=flowed Dear Andrew, this is how you write a double precision real in Fortran. In other words: It's more or less equivalent to 6.626E-34. Although you should note that this is a really small number and issues of precision might actually be pertinent here. Best regards, Hannes On 2022-01-11 18:57, Andrew DeYoung andrewdaviddeyoung###gmail.com wrote: > 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 addition 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 > sometimes historical origins and meanings of notation!) > > Best, > Andrew > > Andrew DeYoung, PhD > Department of Chemistry > Carnegie Mellon University --=_75e476819f659470b0ecc452b4c18101 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=UTF-8

Dear Andrew,

this is how you write a double precision real in Fortran. In other words= : It's more or less equivalent to 6.626E-34. Although you should note that = this is a really small number and issues of precision might actually be per= tinent here.

Best regards,

Hannes

On 2022-01-11 18:57, Andrew DeYoung andrewdaviddeyoun= g###gmail.com wrote:

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 t= his represents 6.626*10^(-34), and is equivalent to the scientific not= ation 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= addition 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 s= ometimes historical origins and meanings of notation!)

Best,

Andrew

Andrew DeYoung, PhD

Department of Chemistry

Carnegie Mellon University

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