Atmospheric pressure formula?

Atmospheric pressure formula?

Atmospheric pressure can not be calculated by the formula P = ρ air GH (or P = R air g)
1. The pressure produced by gas is also related to the collision between molecules
2. The density of the atmosphere is variable. The density of the air near the ground is larger and smaller with the increase of altitude;
3. How to determine the value of H? We should know that there is no obvious interface at the upper end of the atmosphere
When the altitude is less than 2km, it is generally calculated by the isothermal pressure formula