1. The problem statement, all variables and given/known data I'm trying to perform a molecular orbital analysis of a tungsten hydride complex, (WH6) and I haven't been able to find an intuitive or basic definition for a "d0 complex". Every time I read an article about a d0 complex they tangentially mention them and then jump into the problem. 2. Relevant equations What is the definition of a d0 complex? 3. The attempt at a solution I thought it referred to any complex where the d orbital electrons do not directly participate in the bonding between the metal and its ligands. I just want a pure definition. Thank you so much.