The electron distribution characteristics in various chemical systems are highly consistent; that is, the overall distribution of electron density decreases exponentially from each nucleus to the surrounding areas. As a result, directly plotting the total electron density typically does not provide useful information for studying chemical bonds. The valence electron density ( val ) refers to the electron density obtained by removing the contribution of inner electrons from the total electron density. We have found that the  val map is very useful for studying covalent bonding in many cases. Not only is its visualization as intuitive as that of ELF, LOL, and  def , but its calculation is also straightforward (only the inner core orbitals need to be excluded when calculating the electron density) and less time-consuming (as there is no need to compute derivatives of the electron density or wavefunction). However, the value of  val in bonding analysis has long been underestimated.