I am performing a nonlinear dynamic analysis of a structure following the direct integration method using SAP2000. Now, the SAP2000 manual encourages you to set the Hilber-Hughes-Taylor alpha coefficient at a value ranging from 0 to -1/3 in order to attain convergence in analysis. How to decide the value of this coefficient? In a typical case, I am not getting convergence using alpha of -0.01 but attaining the same with alpha -1/3. How do I know whether the result that I am obtaining with an alpha value is reliable or not? This is very crucial in my case, since I am trying to identify the collapse point of the structure by doing an incremental dynamic analysis.