A term coined by Margo Schulter to describe the tiny interval between the pythagorean ratio 2107 3-67 and the harmonic minor-7th of ratio 7:4, approximately 0.18903555 (roughly 3/16) cent. It is a 3==7 xenharmonic-bridge.
The ratio of the nanisma is 649037107316853453566312041152512 : 648966242035284859600333477874109 which is much easier to read as 2109 3-67 7-1, or in prime-factor vector notation, the 2,3,5,7-monzo [109 -67, 0 -1 > .
The nanisma also describes the difference between 2108 3-68 and the septimal minor-3rd of ratio 7:6 (also called "subminor 3rd"), and also the difference between 2-109 369 and the wide septimal major-3rd of ratio 9:7.
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