MD simulation with forcite

I want to simulate water and acetonitrle at 1 am and 298.15 k with forcite tools. I have some question as bellow:

1- I simulate NVT and plot pressure and density, in this step ensity dose not reach to  experimental value.

Then I run NPT at 1 am and 298.15 k for 1ns but density dose not reach the to  experimental value. what is the problem?

2-Another quastion is that when we run NVT ensemble in forcite, the material studio generate .xsd file and .xtd. As I know the .xsd is the final structure of the run and the .xtd is trajectory file, so the final frame of .atd must be the same with .xsd. but I dond find this situation.

3- I want to run NPT following NVT, but I dont know that .xsd or .xtd is useful for the initiation of NPT?