Structural, elastic, electronic, optical and anisotropy properties of newly quaternary Tl2HgGeSe4 via DFPT predictions associated to XPES and RS experiments oleh Mohamed Salah Halati, Oleg Yu Khyzhun, Abderrazak Khireddine, Michal Piasecki, Ilona Radkowska, Khaled Hamdi Cherif, Zakia Lounis, Yves Caudano, Abdelhak Bedjaoui, Ahmed Alghamdi, Prabhu Paramasivam, Chander Prakash, Sherif S. M. Ghoneim