CCL:G: Scientific notation in Gaussian 16

D means double precision as I recall.  I vaguely remember q appearing somewhere when quad precision was used.  E would be single precision.  They’re all scientific notation as you surmise.


On Tue, Jan 11, 2022 at 2:13 PM Andrew DeYoung <owner-chemistry/./> wrote:

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!)


Andrew DeYoung, PhD
Department of Chemistry
Carnegie Mellon University
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