Spaces can be used between compounds to help achieve the spacing you require.
A space IN a compound breaks the compound into two separate pieces from FX ChemStruct's point of view. FX ChemStruct will NOT try to attach the second part to the first. Often this will mean that what you have typed no longer makes sense.
ch3cooh
ch3c ooh
A space is often necessary with ionic compounds
caso4
ca so4
