### Comprehensive Calculation

Here, the model determines the equilibrium state of a system containing water, and two or more ions. Water content is specified either in terms of amount, or as a fixed relative humidity. The formation of solids, and the partitioning of water and individual trace gases between the condensed and vapour phases, can be calculated at the choice of the user.
• Inputs: temperature, ambient relative humidity (expressed as a fraction) or total moles of water per m3 of atmosphere, and the numbers of moles of each ion and NH3 present in the same volume.
• Outputs: the amounts of liquid and gas phase water, dissolved ions, solids, and trace gases present at equilibrium. The partial pressures or partial pressure products of any NH3, HCl, HNO3, or H2SO4 that would be in equilibrium with the condensed phase are also reported.
• Main options: control of the formation of solid phases, the partitioning of trace gases, and equilibration of the system to the water vapour pressure above ice.
Specify the problem in the input fields below.

#### Ambient Conditions

(1) Temperature (180 - 330 K):   (See inputs for details of restrictions on the temperature range, related to the chemical composition of the system.)

(2) The water content of the system must be specified as either a (fixed) ambient relative humidity or the number of moles of water present per m3 of atmosphere. Select one:

 Fixed relative humidity Constant total water

Now enter the relative humidity (range 0.1 - 1.0) or moles of water present:

(3) If the temperature is less than 273.15 K, and you wish the system to be equilibrated to the water vapour pressure over ice, then check the box here. (If constant total water has been selected then this option has no effect.)

#### Inorganic Composition in Moles per m3

 H+: NH4+: Na+: NH3 (ammonia): SO42−: NO3−: Cl−:

#### Other Chemical Components

The amounts of organic compounds present can be entered here. First, click the button to select compounds from the library or create new ones for this session.

#### Trace Gases

Check the boxes below to disable the partitioning of selected trace gases into the vapour phase. (The default for each gas is that partitioning is calculated.)

Prevent partitioning of the following gases:

 HNO3 HCl NH3 H2SO4

#### Solid Phases

Check the boxes below to prevent the formation of selected solids, according to the restrictions that apply for this model. This enables the properties of metastable, supersaturated, aqueous aerosols to be investigated. The default for each calculation is that all solids can form.

No boxes should be checked for any systems containing both NH4+ and Cl ions.

Omit the following solids:

 Ice H2SO4 · H2O H2SO4 · 2H2O H2SO4 · 3H2O H2SO4 · 4H2O H2SO4 · 6.5H2O HNO3 · H2O HNO3 · 2H2O HNO3 · 3H2O HCl · 3H2O (NH4)2SO4 (NH4)3H(SO4)2 NH4HSO4 NH4NO3 2NH4NO3 · (NH4)2SO4 3NH4NO3 · (NH4)2SO4