A reactor is building in SpaceChem, where atoms and molecules are manipulated. Each reactor has a maximum of two inputs, and two outputs - although not all may be available or required.
Inside each reactor is the reactor grid area. This is a 10x8 rectangular grid, where instructions are placed in order to manipulate atoms and molecules.
In Research Assignments, the player will be presented with typically one reactor. As such, you will not be able to move to an external view to see the building. In Production & Defense Assignments, you will be able to enter and leave multiple reactors - and have a distinct reactor grids to manipulate. You will also be able to designate the location of the Reactor buildings, and choose Pipeline connections between them.
Gameplay[]
There are different types of reactors:
Standard Reactor[]
This allows two inputs, two outputs and + or - bonding. Earlier versions of this reactor are presented without bonding functions.
Disassembly Reactor[]
This allows only one input, two outputs, and only - bonding.
Assembly Reactor[]
This allows two inputs, one output, and only + bonding.
Sensor Reactor[]
This allows two inputs and two outputs, and bonding, just as the Standard Reactor. However, this also contains a sensor function - which will carry out instructions based on which particular atom passes over it.
Fusion Reactor[]
This allows two inputs and two outputs, and bonding, just as the Standard Reactor. However, this also contains a fusion function to combine atoms together - thus creating a new atom.
Super-Bonder Reactor[]
Like the Standard Reactor but contains 8 bonders -- double the amount the Standard Reactor does.
Laser Reactor (weapon)[]
The Variable Gain Medium laser, VGM, is present in the Defense assignment of the sixth planet, Hephaestus IV, see. The VGM laser has two normal inputs but no outputs. There is, however, a large output area. The output is not triggered with an instruction but by feeding a xenon atom into the third input. The firing is not instant, though, as the laser apparently needs some time to power up after each shot.
Quantum Junction Reactor[]
The Quantum Junction Reactor contains a teleporter that removes all bonds from the atom it is teleporting, which is needed to move molecules past the physical barrier that separates the input and output areas. It can also be augmented with a spectrometer and can possess 0-4 bonders (depending on the assignment). These reactors can be found in the 63 Corvi expansion.