Scheme

Grid

(1,2,3,4) scheme

(1,2,3,5) scheme

(1,2,4,5) scheme

(1,3,4,5) scheme

Grid 1

−1.9920387

(0.398%)

−1.9917441

(0.412%)

−1.990900404

(0.454%)

−1.986352479

(0.682%)

Grid 2

−1.996072644

(0.196%)

−1.995920807

(0.203%)

−1.99548624

(0.225%)

−1.99313533

(0.343%)

Grid 3

−1.997366868

(0.131%)

−1.997266348

(0.136%)

−1.996973186

(0.151%)

−1.995385341

(0.231%)

Grid 4

−1.984135078

(0.793%)

−1.983628605

(0.818%)

−1.981979149

(0.901%)

−1.973188713

(1.341%)

Grid 5

uniform

−1.92467676435

(3.766%)

−1.92229302

(3.885%)

−1.917526191

(4.124%)

−1.903225703

(4.838%)