In this theoretical study, two novel quaternary Heusler FeRhAlMn and MnAlFeRh alloys have been proposed. FeRhAlMn and MnAlFeRh have the X-type Heusler structure and are half-metallic ferrimagnets, therefore have prospects for use in spintronics device.Исследование выполнено при поддержке гранта Российского научного фонда 22-42-02021