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sobereva

Tian Lu (Multiwfn developer)

From: Beijing

Registered: 2017-09-11

Posts: 1,770

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Notification: Significant improvement of IGM analysis in Multiwfn 3.7

Today I uploaded the new Multiwfn 3.7(dev) to Multiwfn website. There are three major changes about the independent gradient model (IGM) analysis:

(1) The code used to calculate atom pair dg index has been completely rewritten. Originally, the index is calculated based on evenly distributed grid, the accuracy is relatively poor. In the new version, it is calculated based on multi-center integration grid, the accuracy is significantly improved, while the cost is markedly lowered. Due to the significant change of the integration algorithm, you will find the result calculated by the new version is somewhat different to that by old versions (usually, the difference should be less than 5%).

(2) A new form of IGM proposed by me very recently has been implemented in Multiwfn, it is named as IGMH. Please check Section 3.23.6 of the manual for detail. The advantage of IGMH over the original IGM is illustrated in the example given in Section 4.20.11.

(3) The intrinsic bond strength index (IBSI) proposed in J. Phys. Chem. A, 124, 1850 (2020) is defined in the framework of IGM. Now it can be directly calculated by a new function in bond order analysis module. Please check Section 3.11.9 for introduction of this function as well as Section 4.9.6 for example.