Fractional jet Captain reported the non-towered airport chart was inadequate and does not properly describe the hazards associated with the runway width and its insufficient room for back-taxiing. There also was not enough room for parking and the flight crew temporarily parked the aircraft with the left wing over the landing runway environment; as there were other aircraft occupying the ramp area.

Narrative

This is just a report to highlight the inadequacies of this airport and ramp space which could create a safety issue. There is only one chart in JeppFD for this airport and it's of very low definition and is inadequate. During our approach; Aircraft Y called us to tell us he and Aircraft Z were on the ramp and that his right wing was close to the line separating the ramp from the runway. My partner was flying from the right seat and he is new to the plane; so he asked me to take the controls for landing. I did. Upon short final; it looked to me that there was enough runway width for us to land and we landed uneventfully. We back-taxied to the ramp; but there was inadequate space for us. Along with the 2 aforementioned jets; there were 2 single engine prop planes tied down and occupying the ramp. We had no choice to park our plane with our left wing well over into the landing runway environment. We shut down the engines and left the APU running and I had my partner monitor CTAF or warn away any potential arrivals. I talked with the crew of both jets and I ended up asking the Aircraft Z crew if I could have his parking spot once he back-taxied out for takeoff. That is what we ended up doing. For about 30 to 40 minutes; our jet was protruding into the runway environment.We need a better chart for this airport. The one we have is of such low quality it's almost useless. Somehow; we need to know how many jets are on the ramp before we arrive so we can make a proper decision to divert. Crews need more information about the challenges with this airport/ramp space/runway environment before they arrive so they can make better decisions. Aircraft X's wings are very long. We may want to consider only bringing in Aircraft A's with shorter wing spans. I would consider this one of the most dangerous airport environments I have ever flown into.