Circuit Element Reference

Component Syntax
Special Functions Axx n1 n2 n3 n4 n5 n6 n7 n8
+ <model> [extra parameters]
Arbitrary Behavioral SourceBxx n+ n- <V=... or I=...>
Capacitor Cxx n+ n- <capacitance>
+ [ic=<val.>] [Rser=<val.>]
+ [Lser=<val.>] [Rpar=<val.>]
+ [Cpar=<val.>] [m=<val.>]
Diode Dxx A K <model> [area]
Voltage Dependent Voltage Exx n+ n- nc+ nc- <gain>
Current Dependent Current Fxx n+ n- <Vnam> <gain>
Voltage Dependent Current Gxx n+ n- nc+ nc- <transcond.>
Current Dependent Voltage Hxx n+ n- <Vnam> <transres.>
Independent Current source Ixx n+ n- <current>
JFET Transistor Jxx D G S <model> [area] [off]
+[IC=<Vds,Vgs>] [temp=<T>]
Mutual Inductance Kxx L1 L2 L3... <coeff.>
Inductance Lxx n+ n- <inductance>
+ [ic=<val.>] [Rser=<val.>]
+ [Rpar=<val.>]
+ [Cpar=<val.>] [m=<val.>]
MOSFET Transistor Mxx D G S B <model> [L=<len>]
+ [W=<width>] [AD=<area>]
+ [AS=<area>] [PD=<perim>]
+ [PS=<perim>] [NRD=<value>]
+ [NRS=<value>] [off]
+ [IC=<Vds, Vgs, Vbs>
+ [temp=<T>]
Lossy Transmission Line Oxx L+ L- R+ R- <model>
Bipolar Transistor Qxx C B E [S] <model> [area]
+ [off] [IC=Vbe,Vce][temp=<T>]
Resistor Rxx n1 n2 <value>
Voltage Controlled Switch Sxx n1 n2 nc+ nc- <model>
+ [on,off]
Lossless Transmission Line Txx L+ L- R+ R- ZO=<value>
+ TD=<value>
Uniform RC-line Uxx n1 n2 ncommon <model>
+ L=<len> [N=<lumps>]
Independent Voltage Source Vxx n+ n- <voltage>
Current Controlled Switch Wxx n1 n2 <Vnam> <model>
+ [on,off]
Subcircuit Xxx n1 n2 n3... <subckt name>
MESFET Transistor Zxx D G S model [area] [off]
+ [IC=<Vds,Vgs>]

An invaluable reference that complements the LTspice help documentation is the 2nd Edition of Semiconductor Device Modeling with SPICE by Giuseppe Massobrio and Paolo Antognetti, McGraw Hill, 1993 and later reprints. That book documents the semiconductor device equations and extensions that have been used in various commercial SPICE programs including those used in this one. For BSIM 3 and 4 devices, see the relevant documentation available from the UC Berkeley CAD group.