Treballs Finals de Grau de Física, Facultat de Física, Universitat de Barcelona, Curs: 2017, Tutor: Mario Centelles AixalàWe present a study on the negative hydrogen ion, particularly following the works of Chandrasekhar [1, 2]. The conditions for the stability of this system are discussed as well as the methods used to achieve it. We also present the full analytical expression of the variational energy for a Chandrasekhar correlated wave function. Further, we stress the special structure concerning this ion in comparison with the other two-electron system
