Theoretical concepts and calculation results of the spatial parity nonconserving (PNC) effects of electron-electron and electron-nucleus nuclear spin-independent interactions in diatomic homonuclear molecule H₂ of parahydrogen are presented. The magnetic dipole transition between the states with the same rotational number of the vibrational band in the H₂ ground electronic state is considered. It is shown that in this situation these effects are of the same order of magnitude. The H₂ molecule is therefore the first example of molecular system where the electron-electron PNC interaction can be directly observed. Since the constants of the electron-nucleus PNC interaction have been already accurately measured in atomic experiments, the electron-electron PNC interaction constant also can be extracted from the future experiments. In other atoms and molecules the electron-electron PNC interaction is usually deeply screened by the electron-nucleus one. Since the nuclei of H₂ contain no neutrons, in such future experiments on the PNC effect observation one can, in principle, measure the Weinberg angle (free parameter of the standard model) with unprecedented accuracy.