Voigt function 

https://doi.org/10.1351/goldbook.08298
Convolution of Gaussian and Lorentzian (Cauchy) functions.
Source:
PAC, 2021, 93, 647. 'Glossary of methods and terms used in analytical spectroscopy (IUPAC Recommendations 2019)' on page 678 (https://doi.org/10.1515/pac-2019-0203)