hb simulation of imd

In ADS2004A => DesignGuide => Mixer => Single-end mixer characterization => 2nd- and 3rd-order IMD and conv. gain example,
HB simulation controller is set up as following:

MaxOrder=6
Freq[1]=LOfreq
Freq[2]=RFfreq + Fspacing/2
Freq[2]=RFfreq - Fspacing/2
Order[1]=9
Order[2]=3
Order[3]=3
OrderSample[1]=1
OrderSample[2]=1
OrderSample[3]=1
UseKrylov=yes

and in variable decralation there are:

VAR
LOfreq = 900 MHz
RFfreq = 1100 MHz
Fspacing = 200 kHz
P_RF = -30 dBm
P_LO = 0 dBm


Now, I want to use the simulation setup for my Mixer design, pHEMT resistive passive mixer where:
LOfreq = 2350 MHz
RFfreq = 2400 MHz
P_RF = 0 dBm
P_LO = 15 dBm
Fspacing = 1 MHz

Anyone could tell me what value should I set or how I can decide the value of MaxOrder and Order for LO and input RF tones when I want to simulate the IIP3 of the designed mixer?

Also, I read somewhere that

MaxOrder ≥|k1| + |k2| + ... + |kn|

where kn is the harmonic for the nth tone in the circuit.
Can k1 be not integer? or why in the inequality, there need to use the absolute of kn?

Anyone can help plz!