Only recent updates are shown here. To check full update history since the first release (Nov, 2009), please click: UpdateHistory.txt

- The local total/dynamic/nondynamic electron correlation function proposed in J. Chem. Theory Comput., 13, 2705 (2017) now is supported as user-defined function 87,88,89, respectively. These functions are useful for vividly revealing electron correlation in various molecular regions. See corresponding entries in Section 2.7 for detail. Illustrative application is given in part 2 of Section 4.A.6.
- Spectrum of multiple systems now can be easily plotted together, see Section 4.11.6 for example.

- ORCA output file has been supported for hole-electron analysis module, see Section 3.21.1.2 for detail. (Unfortunately, since current ORCA can only print configuration coefficients whose magnitude is larger than 0.01, the analysis result is not quite accurate)
- Better compatible with G16
- Anharmonic Raman and Anharmonic VCD spectra now can be plotted by main function 11 based on Gaussian output file of freq(raman,anharm) and freq(VCD,anharm) task, respectively (the latter is available only for G16)

- Hirshfeld-I (i.e. iterative Hirshfeld) is supported to calculate atomic charges, orbital composition and perform fuzzy space analysis. Please check Section 3.9.13 of the manual for introduction of its theory and implementation. Illustrative examples of using Hirshfeld-I to calculate atomic charges is given in Section 4.7.4
- Single exponential decay detector (SEDD) and Density overlap regions indicator (DORI) proposed in J. Chem. Theory Comput., 10, 3745 (2014) are supported as user-defined function 19 and 20, respectively. The advantage of DORI is that it can simultaneously reveal covalent and non-covalent interaction regions, and the pattern is similar to ELF+RDG. An example of using DORI is given at the end of Section 4.100.1.
- On-top pair density is supported as user-defined function 36.
- X, Y, Z component of Hamiltonian kinetic energy density have been added as 81, 82, 83th user-defined function, respectively. The counterpart of Lagrangian kinetic energy density have been supported as 84, 85, 86th user defined function, respectively.
- A new method to define plotting plane is added to main function 4 as mode 7. Via this mode one can directly define a plane parallel to a bond and meantime normal to a plane defined by three atoms. See Section 3.5.2 of the manual for detail.
- Pre-resonance Raman spectrum now can be plotted by option 2 of main function 11. Program will prompt the user to select the interested frequency of incident light.
- Subfunction 11 of main function 100 is greatly extended, now it can calculate both centroid distance and overlap between two orbitals. See Section 3.100.13 of the manual for details.
- By using option 4 and 8 of subfunction 2 of main function 100, .wfx file and NBO .47 file can be exported, respectively, the former is input file of GENNBO program.
- Pipek-Mezey orbital localization is supported as subfunction 13 of main function 200, please check Section 3.200.13 for detail and 4.200.13 for example.
- Energy of AdNDP orbitals now can be printed. Please check Section 3.17 for detail, the AdNDP examples in Section 4.14.1 and 4.14.3 have been correspondingly updated.
- Any real space function now can be integrated within isosurface of a given real space function by subfunction 14 of main function 200. Please check Section 3.200.14 of the manual for detail and Section 4.200.14 for example.
- A powerful EDF library provided by Wenli Zou is built-in. Now by default, if input file contains atoms using pseudopotential basis set, Multiwfn will automatically find proper EDF information for them to provide representation of inner-core density. See Appendix 4 of the manual for detail. (For .wfx file produced by Gaussian, by default Multiwfn still loads EDF field from this file rather than from the built-in EDF library).
- Natural transition orbital (NTO) analysis is supported as subfunction 6 of main function 18, please check Section 3.21.6 for detail and Section 4.18.4 for example.
- Coulomb attractive energy between hole and electron of an electronic excitation now can be calculated at post-process menu of subfunction 1 of main function 18, please check Section 3.21.1 for detail. The example in Section 4.18.1 is correspondingly updated.
- Conformational weighted spectrum and spectrum of multiple conformations now can be very conveniently plotted by main function 11. Please check Section 3.13.4 for detail and Section 4.11.4 for example. In addition, option 4 and 5 of spectrum plotting interface is improved, namely when changing setting of Y-axis at one side, you can choose to proportionally update range of Y-axis at another side so that their zero points are always in the same horizonal line.

- 32bit Windows version of Multiwfn will no longer be released. Since Multiwfn 3.4 only 64bit version will be released.
- The graphical effect of isosurface plotting has been improved, especially for transparent style
- When drawing isosurface with Linux and MacOS version, the requirement of the equal number of grids in X,Y,Z is removed.
- The style of atomic labels in plane map drawn by main function 4 now can be directly set by option 18 in post-process menu
- Two useful ways to check sanity of wavefunction are introduced as Appendix 4 of the manual
- The function of loading NBO plot file becomes more robust.
- .wfn file generated by Windows version of ORCA 4.0 is supported, and that generated by old version of ORCA is no longer supported
- GAMESS-US output file now can be used as input file (not comprehensively tested, currently only single point task at HF/DFT level is formally supported). The suffix of output file should be changed to .gms so that Multiwfn can properly recognize it
- Subfunction 7 of main function 6 now can output various kinds of integral matrix between basis functions, including overlap integrals, electric/magnetic dipole moment integrals, kinetic energy integrals and velocity integrals
- Density matrix in .fch will no longer be tentatively loaded since this version
- Atomic index in .molden file now is interpreted by Multiwfn as nuclear charge. Therefore, when pseudo-potential is used, you can manually change atomic index in the file so that Multiwfn can correctly recognize actual nuclear charge
- Loading speed of .fch and .molden file for large wavefunction is significantly improved

- Fixed a bug when loading NBO plot file with mixed spherical and cartesian shells.

- Region of Slow Electrons (RoSE), which was proposed in Chem. Phys. Lett., 582, 144 (2013), now is supported as the 18th user defined function.
- Subfunction 100 is added to main function 8, this new function implements the LOBA method (Phys. Chem. Chem. Phys., 11, 11297) for evaluating oxidation state based on localized MOs. See Section 3.10.7 of the manual for introduction and Section 4.8.4 for example.
- Subfunction 20 is added to main function 100. This function is used to calculate Hellmann-Feynman force at each nucleus. See Section 3.100.20 of the manual for details.
- Option -1 added to population analysis module for defining fragment. Once the fragment is defined, after the calculation of atomic charges, the fragment charge will be printed together.

- In the output of multi-center bond order calculation, the result in normalized form is printed, this makes multi-center bond order comparable for different ring sizes. In addition, for open-shell cases, the definition of alpha and beta multi-center bond orders changed and became more meaningful by taking a ring-size dependent prefactor into account. see Section 3.11.2 of the manual for details. The definition of multi-center DI is similarly changed, see Section 3.18.10.
- Now it is possible to compile Multiwfn without GUI supported, please check "COMPLIATION METHOD.txt" in source code package. In this case you don't need Dislin and Openmotif graphical library when running and compiling Multiwfn.
- Windows 10 is now formally supported. In Win10, old version of Multiwfn will get stuck for about 1~2 minutes when first time enter GUI.
- Output file of Gaussian excited state optimization task now can be directly used as input file of main function 11 for plotting electronic spectrum.
- After performing quantitative molecular surface analysis, the density estimated according to mass and molecular volume is outputed.
- In option 1 of topology analysis module, user now can input two atomic indices, then corresponding midpoint will be taken as starting point for locating CP. This improvement faciliates locating specific BCP.
- min(A,B) operation is added to option 11 of main function 13, which is useful for evaluating overlap between function of two moieties. Section 4.13.7 is correpondingly added to manual to illustrate using this feature to evaluate electron density overlap region between two methanes.
- When drawing gradient lines map by main function 4, the line width of gradient lines now can be set by option 14 in post-process menu.
- In main function menu, users now can directly use option -11 (a hidden option) to reload a new file.
- In option 1 of subfunction 5 of main function 100, the maximum pairing between Alpha and Beta orbitals of unrestricted wavefunction now can be shown.
- iatmlabtype3D parameter is added to settings.ini, one can choose if atomic labels or indices will be shown in 3D map.

- Solved crash problem when performing multi-center bond order analysis based on NBO6 output in case of presence of linear dependency of basis functions.

- Multiwfn now can be installed on OS X EI Capitan, see https://wiki.ch.ic.ac.uk/wiki/index.php?title=Mod:multiwfn, thanks Henry Rzepa for sharing his experiences!